Created by William Kapke
kangax's compat-table applied only to Node.js
githubLearn more

Node.js ES2015 Support

14.0.0
(these versions have identical results)
nightly v8 7.8.279.17-node.19
Nightly!99% complete99% complete 		13.0.1
(these versions have identical results)
13.0.1 v8 7.8.279.17-node.14
13.0.0 v8 7.8.279.17-node.14
12.13.0 v8 7.7.299.13-node.12
12.12.0 v8 7.7.299.13-node.12
12.11.1 v8 7.7.299.11-node.12
12.11.0 v8 7.7.299.11-node.12
99% complete99% complete 		12.10.0
(these versions have identical results)
12.10.0 v8 7.6.303.29-node.16
12.9.1 v8 7.6.303.29-node.15
12.9.0 v8 7.6.303.29-node.15
99% complete99% complete 		12.8.1
(these versions have identical results)
12.8.1 v8 7.5.288.22-node.16
12.8.0 v8 7.5.288.22-node.16
12.7.0 v8 7.5.288.22-node.16
12.6.0 v8 7.5.288.22-node.14
12.5.0 v8 7.5.288.22-node.14
99% complete99% complete 		12.4.0
(these versions have identical results)
12.4.0 v8 7.4.288.27-node.18
12.3.1 v8 7.4.288.27-node.18
12.3.0 v8 7.4.288.27-node.17
12.2.0 v8 7.4.288.21-node.17
12.1.0 v8 7.4.288.21-node.16
12.0.0 v8 7.4.288.21-node.16
99% complete99% complete 		11.15.0
(these versions have identical results)
11.15.0 v8 7.0.276.38-node.19
11.14.0 v8 7.0.276.38-node.18
11.13.0 v8 7.0.276.38-node.18
11.12.0 v8 7.0.276.38-node.18
11.11.0 v8 7.0.276.38-node.18
11.10.1 v8 7.0.276.38-node.17
11.10.0 v8 7.0.276.38-node.17
11.9.0 v8 7.0.276.38-node.16
11.8.0 v8 7.0.276.38-node.16
11.7.0 v8 7.0.276.38-node.16
11.6.0 v8 7.0.276.38-node.13
11.5.0 v8 7.0.276.38-node.13
11.4.0 v8 7.0.276.38-node.13
11.3.0 v8 7.0.276.38-node.11
11.2.0 v8 7.0.276.38-node.11
11.1.0 v8 7.0.276.32-node.7
11.0.0 v8 7.0.276.28-node.5
99% complete99% complete 		10.17.0
(these versions have identical results)
10.17.0 v8 6.8.275.32-node.54
10.16.3 v8 6.8.275.32-node.54
10.16.2 v8 6.8.275.32-node.54
10.16.1 v8 6.8.275.32-node.54
10.16.0 v8 6.8.275.32-node.52
10.15.3 v8 6.8.275.32-node.51
10.15.2 v8 6.8.275.32-node.12
10.15.1 v8 6.8.275.32-node.12
10.15.0 v8 6.8.275.32-node.45
10.14.2 v8 6.8.275.32-node.45
10.14.1 v8 6.8.275.32-node.36
10.14.0 v8 6.8.275.32-node.36
10.13.0 v8 6.8.275.32-node.36
10.12.0 v8 6.8.275.32-node.35
10.11.0 v8 6.8.275.32-node.28
10.10.0 v8 6.8.275.30-node.24
10.9.0 v8 6.8.275.24-node.14
99% complete99% complete 		10.8.0
(these versions have identical results)
10.8.0 v8 6.7.288.49-node.19
10.7.0 v8 6.7.288.49-node.15
10.6.0 v8 6.7.288.46-node.13
10.5.0 v8 6.7.288.46-node.8
10.4.1 v8 6.7.288.45-node.7
10.4.0 v8 6.7.288.43-node.7
99% complete99% complete 		10.3.0
(these versions have identical results)
10.3.0 v8 6.6.346.32-node.9
10.2.1 v8 6.6.346.32-node.8
10.2.0 v8 6.6.346.32-node.8
10.1.0 v8 6.6.346.27-node.6
10.0.0 v8 6.6.346.24-node.5
99% complete99% complete 		9.11.2
(these versions have identical results)
9.11.2 v8 6.2.414.46-node.23
9.11.1 v8 6.2.414.46-node.23
9.11.0 v8 6.2.414.46-node.23
9.10.1 v8 6.2.414.46-node.23
9.10.0 v8 6.2.414.46-node.23
9.9.0 v8 6.2.414.46-node.22
9.8.0 v8 6.2.414.46-node.21
9.7.1 v8 6.2.414.46-node.20
9.7.0 v8 6.2.414.46-node.20
9.6.1 v8 6.2.414.46-node.20
9.6.0 v8 6.2.414.46-node.20
9.5.0 v8 6.2.414.46-node.18
9.4.0 v8 6.2.414.46-node.17
9.3.0 v8 6.2.414.46-node.15
9.2.1 v8 6.2.414.44-node.11
9.2.0 v8 6.2.414.44-node.11
9.1.0 v8 6.2.414.32-node.8
9.0.0 v8 6.2.414.32-node.8
8.16.2 v8 6.2.414.78
8.16.1 v8 6.2.414.77
8.16.0 v8 6.2.414.77
8.15.1 v8 6.2.414.75
8.15.0 v8 6.2.414.75
8.14.1 v8 6.2.414.75
8.14.0 v8 6.2.414.72
8.13.0 v8 6.2.414.72
8.12.0 v8 6.2.414.66
8.11.4 v8 6.2.414.54
8.11.3 v8 6.2.414.54
8.11.2 v8 6.2.414.54
8.11.1 v8 6.2.414.50
8.11.0 v8 6.2.414.50
8.10.0 v8 6.2.414.50
99% complete99% complete 		8.9.4
(these versions have identical results)
8.9.4 v8 6.1.534.50
8.9.3 v8 6.1.534.48
8.9.2 v8 6.1.534.48
8.9.1 v8 6.1.534.47
8.9.0 v8 6.1.534.46
8.8.1 v8 6.1.534.42
8.8.0 v8 6.1.534.42
8.7.0 v8 6.1.534.42
99% complete99% complete 		8.6.0
(these versions have identical results)
8.6.0 v8 6.0.287.53
8.5.0 v8 6.0.287.53
8.4.0 v8 6.0.286.52
8.3.0 v8 6.0.286.52
99% complete99% complete 		8.2.1
(these versions have identical results)
8.2.1 v8 5.8.283.41
8.2.0 v8 5.8.283.41
8.1.4 v8 5.8.283.41
8.1.3 v8 5.8.283.41
8.1.2 v8 5.8.283.41
8.1.1 v8 5.8.283.41
8.1.0 v8 5.8.283.41
8.0.0 v8 5.8.283.41
99% complete99% complete 		7.10.1
(these versions have identical results)
7.10.1 v8 5.5.372.43
7.10.0 v8 5.5.372.43
7.9.0 v8 5.5.372.43
7.8.0 v8 5.5.372.43
7.7.4 v8 5.5.372.42
7.7.3 v8 5.5.372.41
7.7.2 v8 5.5.372.41
7.7.1 v8 5.5.372.41
7.7.0 v8 5.5.372.41
7.6.0 v8 5.5.372.40
99% complete99% complete 		7.5.0
(these versions have identical results)
7.5.0 v8 5.4.500.48
7.4.0 v8 5.4.500.45
7.3.0 v8 5.4.500.45
7.2.1 v8 5.4.500.44
7.2.0 v8 5.4.500.43
7.1.0 v8 5.4.500.36
7.0.0 v8 5.4.500.36
99% complete98% complete 		6.17.1
(these versions have identical results)
6.17.1 v8 5.1.281.111
6.17.0 v8 5.1.281.111
6.16.0 v8 5.1.281.111
6.15.1 v8 5.1.281.111
6.15.0 v8 5.1.281.111
6.14.4 v8 5.1.281.111
6.14.3 v8 5.1.281.111
6.14.2 v8 5.1.281.111
6.14.1 v8 5.1.281.111
6.14.0 v8 5.1.281.111
6.13.1 v8 5.1.281.111
6.13.0 v8 5.1.281.111
6.12.3 v8 5.1.281.111
6.12.2 v8 5.1.281.109
6.12.1 v8 5.1.281.109
6.12.0 v8 5.1.281.108
6.11.5 v8 5.1.281.108
6.11.4 v8 5.1.281.108
6.11.3 v8 5.1.281.107
6.11.2 v8 5.1.281.103
6.11.1 v8 5.1.281.103
6.11.0 v8 5.1.281.102
6.10.3 v8 5.1.281.101
6.10.2 v8 5.1.281.98
6.10.1 v8 5.1.281.95
6.10.0 v8 5.1.281.93
6.9.5 v8 5.1.281.89
6.9.4 v8 5.1.281.89
6.9.3 v8 5.1.281.89
6.9.2 v8 5.1.281.88
6.9.1 v8 5.1.281.84
6.9.0 v8 5.1.281.84
6.8.1 v8 5.1.281.84
6.8.0 v8 5.1.281.84
6.7.0 v8 5.1.281.83
6.6.0 v8 5.1.281.83
6.5.0 v8 5.1.281.81
99% complete99% complete 		6.4.0
(these versions have identical results)
6.4.0 v8 5.0.71.60
6.3.1 v8 5.0.71.57
6.3.0 v8 5.0.71.52
6.2.2 v8 5.0.71.52
6.2.1 v8 5.0.71.52
6.2.0 v8 5.0.71.47
6.1.0 v8 5.0.71.35
6.0.0 v8 5.0.71.35
95% complete91% complete 		5.12.0
(these versions have identical results)
5.12.0 v8 4.6.85.32
5.11.1 v8 4.6.85.31
5.11.0 v8 4.6.85.31
5.10.1 v8 4.6.85.31
5.10.0 v8 4.6.85.31
5.9.1 v8 4.6.85.31
5.9.0 v8 4.6.85.31
5.8.0 v8 4.6.85.31
5.7.1 v8 4.6.85.31
5.7.0 v8 4.6.85.31
5.6.0 v8 4.6.85.31
5.5.0 v8 4.6.85.31
5.4.1 v8 4.6.85.31
5.4.0 v8 4.6.85.31
5.3.0 v8 4.6.85.31
5.2.0 v8 4.6.85.31
5.1.1 v8 4.6.85.31
5.1.0 v8 4.6.85.31
5.0.0 v8 4.6.85.28
57% complete46% complete 		4.9.1
(these versions have identical results)
4.9.1 v8 4.5.103.53
4.9.0 v8 4.5.103.53
4.8.7 v8 4.5.103.53
4.8.6 v8 4.5.103.53
4.8.5 v8 4.5.103.47
4.8.4 v8 4.5.103.47
4.8.3 v8 4.5.103.47
4.8.2 v8 4.5.103.46
4.8.1 v8 4.5.103.46
4.8.0 v8 4.5.103.45
4.7.3 v8 4.5.103.43
4.7.2 v8 4.5.103.43
4.7.1 v8 4.5.103.43
4.7.0 v8 4.5.103.43
4.6.2 v8 4.5.103.42
4.6.1 v8 4.5.103.37
4.6.0 v8 4.5.103.37
4.5.0 v8 4.5.103.37
4.4.7 v8 4.5.103.36
4.4.6 v8 4.5.103.36
4.4.5 v8 4.5.103.35
4.4.4 v8 4.5.103.35
4.4.3 v8 4.5.103.35
4.4.2 v8 4.5.103.35
4.4.1 v8 4.5.103.35
4.4.0 v8 4.5.103.35
4.3.2 v8 4.5.103.35
4.3.1 v8 4.5.103.35
4.3.0 v8 4.5.103.35
4.2.6 v8 4.5.103.35
4.2.5 v8 4.5.103.35
4.2.4 v8 4.5.103.35
4.2.3 v8 4.5.103.35
4.2.2 v8 4.5.103.35
4.2.1 v8 4.5.103.35
4.2.0 v8 4.5.103.35
4.1.2 v8 4.5.103.35
4.1.1 v8 4.5.103.33
4.1.0 v8 4.5.103.33
4.0.0 v8 4.5.103.30
47% complete43% complete 		0.12.18
(these versions have identical results)
0.12.18 v8 3.28.71.20
30% complete23% complete 		0.10.48
(these versions have identical results)
0.10.48 v8 3.14.5.11
11% complete6% complete

optimisation

proper tail calls (tail call optimisation)

§direct recursion
?
function(){
"use strict"; return (function f(n){ if (n <= 0) { return "foo"; } return f(n - 1); }(1e6)) === "foo";
}
Error
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§mutual recursion
?
function(){
"use strict"; function f(n){ if (n <= 0) { return "foo"; } return g(n - 1); } function g(n){ if (n <= 0) { return "bar"; } return f(n - 1); } return f(1e6) === "foo" && f(1e6+1) === "bar";
}
Error
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syntax

default function parameters

§basic functionality
?
function(){
return (function (a = 1, b = 2) { return a === 3 && b === 2; }(3));
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Error
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§explicit undefined defers to the default
?
function(){
return (function (a = 1, b = 2) { return a === 1 && b === 3; }(undefined, 3));
}
Yes
Yes
Yes
Yes
Yes
Yes
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Error
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§defaults can refer to previous params
?
function(){
return (function (a, b = a) { return b === 5; }(5));
}
Yes
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Yes
Yes
Yes
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Yes
Error
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§arguments object interaction
?
function(){
return (function (a = "baz", b = "qux", c = "quux") { a = "corge"; // The arguments object is not mapped to the // parameters, even outside of strict mode. return arguments.length === 2 && arguments[0] === "foo" && arguments[1] === "bar"; }("foo", "bar"));
}
Yes
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Yes
Yes
Yes
Yes
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Yes
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Error
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§temporal dead zone
?
function(){
return (function(x = 1) { try { eval("(function(a=a){}())"); return false; } catch(e) {} try { eval("(function(a=b,b){}())"); return false; } catch(e) {} return true; }());
}
Yes
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§separate scope
?
function(){
return (function(a=function(){ return typeof b === 'undefined'; }){ var b = 1; return a(); }());
}
Yes
Yes
Yes
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Yes
Yes
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Error
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§new Function() support
?
function(){
return new Function("a = 1", "b = 2", "return a === 3 && b === 2;" )(3);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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rest parameters

§basic functionality
?
function(){
return (function (foo, ...args) { return args instanceof Array && args + "" === "bar,baz"; }("foo", "bar", "baz"));
}
Yes
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Yes
Yes
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Error
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§function 'length' property
?
function(){
return function(a, ...b){}.length === 1 && function(...c){}.length === 0;
}
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Error
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§arguments object interaction
?
function(){
return (function (foo, ...args) { foo = "qux"; // The arguments object is not mapped to the // parameters, even outside of strict mode. return arguments.length === 3 && arguments[0] === "foo" && arguments[1] === "bar" && arguments[2] === "baz"; }("foo", "bar", "baz"));
}
Yes
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Yes
Yes
Yes
Yes
Yes
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Error
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§can't be used in setters
?
function(){
return (function (...args) { try { eval("({set e(...args){}})"); } catch(e) { return true; } }());
}
Yes
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Yes
Yes
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Error
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§new Function() support
?
function(){
return new Function("a", "...b", "return b instanceof Array && a+b === 'foobar,baz';" )('foo','bar','baz');
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Error
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Error

spread syntax for iterable objects

§with arrays, in function calls
?
function(){
return Math.max(...[1, 2, 3]) === 3
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Error
Flag
No
Error
No
No
§with arrays, in array literals
?
function(){
return [...[1, 2, 3]][2] === 3;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Error
Flag
No
Error
No
No
§with sparse arrays, in function calls
?
function(){
var a = Array(...[,,]); return "0" in a && "1" in a && '' + a[0] + a[1] === "undefinedundefined";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
No
Error
No
No
§with sparse arrays, in array literals
?
function(){
var a = [...[,,]]; return "0" in a && "1" in a && '' + a[0] + a[1] === "undefinedundefined";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
No
Error
No
No
§with strings, in function calls
?
function(){
return Math.max(..."1234") === 4;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
No
Error
No
No
§with strings, in array literals
?
function(){
return ["a", ..."bcd", "e"][3] === "d";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
No
Error
No
No
§with astral plane strings, in function calls
?
function(){
return Array(..."𠮷𠮶")[0] === "𠮷";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
No
Error
No
No
§with astral plane strings, in array literals
?
function(){
return [..."𠮷𠮶"][0] === "𠮷";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
No
Error
No
No
§with generator instances, in calls
?
function(){
var iterable = (function*(){ yield 1; yield 2; yield 3; }()); return Math.max(...iterable) === 3;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
No
Error
No
No
§with generator instances, in arrays
?
function(){
var iterable = (function*(){ yield "b"; yield "c"; yield "d"; }()); return ["a", ...iterable, "e"][3] === "d";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
No
Error
No
No
§with generic iterables, in calls
?
function(){
var iterable = global.__createIterableObject([1, 2, 3]); return Math.max(...iterable) === 3;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
No
Error
No
No
§with generic iterables, in arrays
?
function(){
var iterable = global.__createIterableObject(["b", "c", "d"]); return ["a", ...iterable, "e"][3] === "d";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
No
Error
No
No
§with instances of iterables, in calls
?
function(){
var iterable = global.__createIterableObject([1, 2, 3]); return Math.max(...Object.create(iterable)) === 3;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
No
Error
No
No
§with instances of iterables, in arrays
?
function(){
var iterable = global.__createIterableObject(["b", "c", "d"]); return ["a", ...Object.create(iterable), "e"][3] === "d";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
No
Error
No
No
§spreading non-iterables is a runtime error
?
function(){
try { Math.max(...2); } catch(e) { return Math.max(...[1, 2, 3]) === 3; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
No
Error
No
No

object literal extensions

§computed properties
?
function(){
var x = 'y'; return ({ [x]: 1 }).y === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§shorthand properties
?
function(){
var a = 7, b = 8, c = {a,b}; return c.a === 7 && c.b === 8;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§shorthand methods
?
function(){
return ({ y() { return 2; } }).y() === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§string-keyed shorthand methods
?
function(){
return ({ "foo bar"() { return 4; } })["foo bar"]() === 4;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§computed shorthand methods
?
function(){
var x = 'y'; return ({ [x](){ return 1 } }).y() === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§computed accessors
?
function(){
var x = 'y', valueSet, obj = { get [x] () { return 1 }, set [x] (value) { valueSet = value } }; obj.y = 'foo'; return obj.y === 1 && valueSet === 'foo';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error

for..of loops

§with arrays
?
function(){
var arr = [5]; for (var item of arr) return item === 5;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§with sparse arrays
?
function(){
var arr = [,,]; var count = 0; for (var item of arr) count += (item === undefined); return count === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§with strings
?
function(){
var str = ""; for (var item of "foo") str += item; return str === "foo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§with astral plane strings
?
function(){
var str = ""; for (var item of "𠮷𠮶") str += item + " "; return str === "𠮷 𠮶 ";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§with generator instances
?
function(){
var result = ""; var iterable = (function*(){ yield 1; yield 2; yield 3; }()); for (var item of iterable) { result += item; } return result === "123";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§with generic iterables
?
function(){
var result = ""; var iterable = global.__createIterableObject([1, 2, 3]); for (var item of iterable) { result += item; } return result === "123";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§with instances of generic iterables
?
function(){
var result = ""; var iterable = global.__createIterableObject([1, 2, 3]); for (var item of Object.create(iterable)) { result += item; } return result === "123";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§iterator closing, break
?
function(){
var closed = false; var iter = __createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); for (var it of iter) break; return closed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
Error
Error
§iterator closing, throw
?
function(){
var closed = false; var iter = __createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); try { for (var it of iter) throw 0; } catch(e){} return closed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
Error
Error

octal and binary literals

§octal literals
?
function(){
return 0o10 === 8 && 0O10 === 8;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§binary literals
?
function(){
return 0b10 === 2 && 0B10 === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§octal supported by Number()
?
function(){
return Number('0o1') === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
§binary supported by Number()
?
function(){
return Number('0b1') === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No

template literals

§basic functionality
?
function(){
var a = "ba", b = "QUX"; return `foo bar ${a + "z"} ${b.toLowerCase()}` === "foo bar\nbaz qux";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§toString conversion
?
function(){
var a = { toString: function() { return "foo"; }, valueOf: function() { return "bar"; }, }; return `${a}` === "foo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§tagged template literals
?
function(){
var called = false; function fn(parts, a, b) { called = true; return parts instanceof Array && parts[0] === "foo" && parts[1] === "bar\n" && parts.raw[0] === "foo" && parts.raw[1] === "bar\\n" && a === 123 && b === 456; } return fn `foo${123}bar\n${456}` && called;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§passed array is frozen
?
function(){
return (function(parts) { return Object.isFrozen(parts) && Object.isFrozen(parts.raw); }) `foo${0}bar${0}baz`;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§line break normalisation
?
function(){
var cr = eval("`x" + String.fromCharCode(13) + "y`"); var lf = eval("`x" + String.fromCharCode(10) + "y`"); var crlf = eval("`x" + String.fromCharCode(13,10) + "y`"); return cr.length === 3 && lf.length === 3 && crlf.length === 3 && cr[1] === lf[1] && lf[1] === crlf[1] && crlf[1] === '\n';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§TemplateStrings call site caching
?
function(){
// TemplateStrings caching was changed from per-contents to // per-call-site. // https://github.com/tc39/ecma262/pull/890 function strings(array) { return array; } function getStrings() { return strings`foo`; } var original = getStrings(); var other = strings`foo`; return original === getStrings() && original !== other;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Error
No
No
§TemplateStrings permanent caching
?
function(){
function strings(array) { return array; } function getStrings() { return strings`foo`; } var original = getStrings(); var newed = new getStrings(); return original === getStrings() && original === newed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Error
No
No

RegExp "y" and "u" flags

§"y" flag
?
function(){
var re = new RegExp('\\w', 'y'); re.exec('xy'); return (re.exec('xy')[0] === 'y');
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"y" flag, lastIndex
?
function(){
var re = new RegExp('yy', 'y'); re.lastIndex = 3; var result = re.exec('xxxyyxx')[0]; return result === 'yy' && re.lastIndex === 5;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"u" flag
?
function(){
return "𠮷".match(/^.$/u)[0].length === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"u" flag, non-BMP Unicode characters
?
function(){
return "𠮷x".match(/^.x$/u)[0].length === 3;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
No
Error
No
No
§"u" flag, Unicode code point escapes
?
function(){
return "𝌆".match(/\u{1d306}/u)[0].length === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"u" flag, case folding
?
function(){
return "ſ".match(/S/iu) && "S".match(/ſ/iu);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error

destructuring, declarations

§with arrays
?
function(){
var [a, , [b], c] = [5, null, [6]]; return a === 5 && b === 6 && c === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with sparse arrays
?
function(){
var [a, , b] = [,,,]; return a === undefined && b === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with strings
?
function(){
var [a, b, c] = "ab"; return a === "a" && b === "b" && c === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with astral plane strings
?
function(){
var [c] = "𠮷𠮶"; return c === "𠮷";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with generator instances
?
function(){
var [a, b, c] = (function*(){ yield 1; yield 2; }()); return a === 1 && b === 2 && c === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with generic iterables
?
function(){
var [a, b, c] = global.__createIterableObject([1, 2]); return a === 1 && b === 2 && c === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with instances of generic iterables
?
function(){
var [a, b, c] = Object.create(global.__createIterableObject([1, 2])); return a === 1 && b === 2 && c === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§iterator closing
?
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); var [a, b] = iter; return closed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error
Error
Error
Error
Error
Error
Error
§trailing commas in iterable patterns
?
function(){
var [a,] = [1]; return a === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with objects
?
function(){
var {c, x:d, e} = {c:7, x:8}; return c === 7 && d === 8 && e === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§object destructuring with primitives
?
function(){
var {toFixed} = 2; var {slice} = ''; return toFixed === Number.prototype.toFixed && slice === String.prototype.slice;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§trailing commas in object patterns
?
function(){
var {a,} = {a:1}; return a === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§throws on null and undefined
?
function(){
try { var {a} = null; return false; } catch(e) { if (!(e instanceof TypeError)) return false; } try { var {b} = undefined; return false; } catch(e) { if (!(e instanceof TypeError)) return false; } return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§computed properties
?
function(){
var qux = "corge"; var { [qux]: grault } = { corge: "garply" }; return grault === "garply";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§multiples in a single var statement
?
function(){
var [a,b] = [5,6], {c,d} = {c:7,d:8}; return a === 5 && b === 6 && c === 7 && d === 8;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§nested
?
function(){
var [e, {x:f, g}] = [9, {x:10}]; var {h, x:[i]} = {h:11, x:[12]}; return e === 9 && f === 10 && g === undefined && h === 11 && i === 12;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§in for-in loop heads
?
function(){
for(var [i, j, k] in { qux: 1 }) { return i === "q" && j === "u" && k === "x"; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§in for-of loop heads
?
function(){
for(var [i, j, k] of [[1,2,3]]) { return i === 1 && j === 2 && k === 3; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§in catch heads
?
function(){
try { throw [1,2]; } catch([i,j]) { try { throw { k: 3, l: 4 }; } catch({k, l}) { return i === 1 && j === 2 && k === 3 && l === 4; } }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§rest
?
function(){
var [a, ...b] = [3, 4, 5]; var [c, ...d] = [6]; return a === 3 && b instanceof Array && (b + "") === "4,5" && c === 6 && d instanceof Array && d.length === 0;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§defaults
?
function(){
var {a = 1, b = 0, z:c = 3} = {b:2, z:undefined}; var [d = 0, e = 5, f = 6] = [4,,undefined]; return a === 1 && b === 2 && c === 3 && d === 4 && e === 5 && f === 6;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§defaults, let temporal dead zone
?
function(){
var {a, b = 2} = {a:1}; try { eval("let {c = c} = {};"); return false; } catch(e){} try { eval("let {c = d, d} = {d:1};"); return false; } catch(e){} return a === 1 && b === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error

destructuring, assignment

§with arrays
?
function(){
var a,b,c; [a, , [b], c] = [5, null, [6]]; return a === 5 && b === 6 && c === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with sparse arrays
?
function(){
var a, b; [a, , b] = [,,,]; return a === undefined && b === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with strings
?
function(){
var a,b,c; [a, b, c] = "ab"; return a === "a" && b === "b" && c === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with astral plane strings
?
function(){
var c; [c] = "𠮷𠮶"; return c === "𠮷";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with generator instances
?
function(){
var a,b,c; [a, b, c] = (function*(){ yield 1; yield 2; }()); return a === 1 && b === 2 && c === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with generic iterables
?
function(){
var a,b,c; [a, b, c] = global.__createIterableObject([1, 2]); return a === 1 && b === 2 && c === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with instances of generic iterables
?
function(){
var a,b,c; [a, b, c] = Object.create(global.__createIterableObject([1, 2])); return a === 1 && b === 2 && c === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§iterator closing
?
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); var a,b; [a, b] = iter; return closed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error
Error
Error
Error
Error
Error
Error
§iterable destructuring expression
?
function(){
var a, b, iterable = [1,2]; return ([a, b] = iterable) === iterable;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§chained iterable destructuring
?
function(){
var a,b,c,d; [a,b] = [c,d] = [1,2]; return a === 1 && b === 2 && c === 1 && d === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§trailing commas in iterable patterns
?
function(){
var a; [a,] = [1]; return a === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with objects
?
function(){
var c,d,e; ({c, x:d, e} = {c:7, x:8}); return c === 7 && d === 8 && e === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§object destructuring with primitives
?
function(){
var toFixed, slice; ({toFixed} = 2); ({slice} = ''); return toFixed === Number.prototype.toFixed && slice === String.prototype.slice;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§trailing commas in object patterns
?
function(){
var a; ({a,} = {a:1}); return a === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§object destructuring expression
?
function(){
var a, b, obj = { a:1, b:2 }; return ({a,b} = obj) === obj;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§parenthesised left-hand-side is a syntax error
?
function(){
var a, b; ({a,b} = {a:1,b:2}); try { eval("({a,b}) = {a:3,b:4};"); } catch(e) { return a === 1 && b === 2; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§chained object destructuring
?
function(){
var a,b,c,d; ({a,b} = {c,d} = {a:1,b:2,c:3,d:4}); return a === 1 && b === 2 && c === 3 && d === 4;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§throws on null and undefined
?
function(){
var a,b; try { ({a} = null); return false; } catch(e) { if (!(e instanceof TypeError)) return false; } try { ({b} = undefined); return false; } catch(e) { if (!(e instanceof TypeError)) return false; } return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§computed properties
?
function(){
var grault, qux = "corge"; ({ [qux]: grault } = { corge: "garply" }); return grault === "garply";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§nested
?
function(){
var e,f,g,h,i; [e, {x:f, g}] = [9, {x:10}]; ({h, x:[i]} = {h:11, x:[12]}); return e === 9 && f === 10 && g === undefined && h === 11 && i === 12;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§rest
?
function(){
var a,b,c,d; [a, ...b] = [3, 4, 5]; [c, ...d] = [6]; return a === 3 && b instanceof Array && (b + "") === "4,5" && c === 6 && d instanceof Array && d.length === 0;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§nested rest
?
function(){
var a = [1, 2, 3], first, last; [first, ...[a[2], last]] = a; return first === 1 && last === 3 && (a + "") === "1,2,2";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§empty patterns
?
function(){
[] = [1,2]; ({} = {a:1,b:2}); return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§defaults
?
function(){
var a,b,c,d,e,f; ({a = 1, b = 0, z:c = 3} = {b:2, z:undefined}); [d = 0, e = 5, f = 6] = [4,,undefined]; return a === 1 && b === 2 && c === 3 && d === 4 && e === 5 && f === 6;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error

destructuring, parameters

§with arrays
?
function(){
return function([a, , [b], c]) { return a === 5 && b === 6 && c === undefined; }([5, null, [6]]);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with sparse arrays
?
function(){
return function([a, , b]) { return a === undefined && b === undefined; }([,,,]);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with strings
?
function(){
return function([a, b, c]) { return a === "a" && b === "b" && c === undefined; }("ab");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with astral plane strings
?
function(){
return function([c]) { return c === "𠮷"; }("𠮷𠮶");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with generator instances
?
function(){
return function([a, b, c]) { return a === 1 && b === 2 && c === undefined; }(function*(){ yield 1; yield 2; }());
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with generic iterables
?
function(){
return function([a, b, c]) { return a === 1 && b === 2 && c === undefined; }(global.__createIterableObject([1, 2]));
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with instances of generic iterables
?
function(){
return function([a, b, c]) { return a === 1 && b === 2 && c === undefined; }(Object.create(global.__createIterableObject([1, 2])));
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§iterator closing
?
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); (function([a,b]) {}(iter)); return closed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error
Error
Error
Error
Error
Error
Error
§trailing commas in iterable patterns
?
function(){
return function([a,]) { return a === 1; }([1]);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§with objects
?
function(){
return function({c, x:d, e}) { return c === 7 && d === 8 && e === undefined; }({c:7, x:8});
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§object destructuring with primitives
?
function(){
return function({toFixed}, {slice}) { return toFixed === Number.prototype.toFixed && slice === String.prototype.slice; }(2,'');
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§trailing commas in object patterns
?
function(){
return function({a,}) { return a === 1; }({a:1});
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§throws on null and undefined
?
function(){
try { (function({a}){}(null)); return false; } catch(e) {} try { (function({b}){}(undefined)); return false; } catch(e) {} return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§computed properties
?
function(){
var qux = "corge"; return function({ [qux]: grault }) { return grault === "garply"; }({ corge: "garply" });
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§nested
?
function(){
return function([e, {x:f, g}], {h, x:[i]}) { return e === 9 && f === 10 && g === undefined && h === 11 && i === 12; }([9, {x:10}],{h:11, x:[12]});
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§'arguments' interaction
?
function(){
return (function({a, x:b, y:e}, [c, d]) { return arguments[0].a === 1 && arguments[0].x === 2 && !("y" in arguments[0]) && arguments[1] + '' === "3,4"; }({a:1, x:2}, [3, 4]));
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§new Function() support
?
function(){
return new Function("{a, x:b, y:e}","[c, d]", "return a === 1 && b === 2 && c === 3 && " + "d === 4 && e === undefined;" )({a:1, x:2}, [3, 4]);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§in parameters, function 'length' property
?
function(){
return function({a, b}, [c, d]){}.length === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§rest
?
function(){
return function([a, ...b], [c, ...d]) { return a === 3 && b instanceof Array && (b + "") === "4,5" && c === 6 && d instanceof Array && d.length === 0; }([3, 4, 5], [6]);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§empty patterns
?
function(){
return function ([],{}){ return arguments[0] + '' === "3,4" && arguments[1].x === "foo"; }([3,4],{x:"foo"});
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§defaults
?
function(){
return (function({a = 1, b = 0, c = 3, x:d = 0, y:e = 5}, [f = 6, g = 0, h = 8]) { return a === 1 && b === 2 && c === 3 && d === 4 && e === 5 && f === 6 && g === 7 && h === 8; }({b:2, c:undefined, x:4},[, 7, undefined]));
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§defaults, separate scope
?
function(){
return (function({a=function(){ return typeof b === 'undefined'; }}){ var b = 1; return a(); }({}));
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§defaults, new Function() support
?
function(){
return new Function("{a = 1, b = 0, c = 3, x:d = 0, y:e = 5}", "return a === 1 && b === 2 && c === 3 && d === 4 && e === 5;" )({b:2, c:undefined, x:4});
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§defaults, arrow function
?
function(){
return ((a, {b = 0, c = 3}) => { return a === 1 && b === 2 && c === 3; })(1, {b: 2});
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error

Unicode code point escapes

§in strings
?
function(){
return '\u{1d306}' == '\ud834\udf06';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§in identifiers
?
function(){
var \u{102C0} = { \u{102C0} : 2 }; return \u{102C0}['\ud800\udec0'] === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error

new.target

§in constructors
?
function(){
var passed = false; new function f() { passed = (new.target === f); }(); (function() { passed &= (new.target === undefined); }()); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
§assignment is an early error
?
function(){
var passed = false; new function f() { passed = (new.target === f); }(); try { Function("new.target = function(){};"); } catch(e) { return passed; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error

bindings

const

§basic support
?
function(){
const foo = 123; return (foo === 123);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§is block-scoped
?
function(){
const bar = 123; { const bar = 456; } return bar === 123;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Flag
§scope shadow resolution
?
function(){
try { { const bar = 456; } const bar = 123; return bar === 123; } catch(e) { return false; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
No
Error
No
No
§cannot be in statements
?
function(){
const bar = 1; try { Function("if(true) const baz = 1;")(); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Error
No
Error
No
§redefining a const is an error
?
function(){
const baz = 1; try { Function("const foo = 1; foo = 2;")(); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Error
No
Error
No
§for loop statement scope
?
function(){
const baz = 1; for(const baz = 0; false;) {} return baz === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Flag
§for-in loop iteration scope
?
function(){
var scopes = []; for(const i in { a:1, b:1 }) { scopes.push(function(){ return i; }); } return (scopes[0]() === "a" && scopes[1]() === "b");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Error
Error
Error
Error
§for-of loop iteration scope
?
function(){
var scopes = []; for(const i of ['a','b']) { scopes.push(function(){ return i; }); } return (scopes[0]() === "a" && scopes[1]() === "b");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Error
Error
Error
Error
§temporal dead zone
?
function(){
var passed = (function(){ try { qux; } catch(e) { return true; }}()); function fn() { passed &= qux === 456; } const qux = 456; fn(); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Error
No
Error
Flag
§basic support (strict mode)
?
function(){
"use strict"; const foo = 123; return (foo === 123);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
§is block-scoped (strict mode)
?
function(){
'use strict'; const bar = 123; { const bar = 456; } return bar === 123;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
§scope shadow resolution (strict mode)
?
function(){
'use strict'; try { { const bar = 456; } const bar = 123; return bar === 123; } catch(e) { return false; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
§cannot be in statements (strict mode)
?
function(){
'use strict'; const bar = 1; try { Function("'use strict'; if(true) const baz = 1;")(); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
§redefining a const (strict mode)
?
function(){
'use strict'; const baz = 1; try { Function("'use strict'; const foo = 1; foo = 2;")(); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
§for loop statement scope (strict mode)
?
function(){
'use strict'; const baz = 1; for(const baz = 0; false;) {} return baz === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
§for-in loop iteration scope (strict mode)
?
function(){
'use strict'; var scopes = []; for(const i in { a:1, b:1 }) { scopes.push(function(){ return i; }); } return (scopes[0]() === "a" && scopes[1]() === "b");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§for-of loop iteration scope (strict mode)
?
function(){
'use strict'; var scopes = []; for(const i of ['a','b']) { scopes.push(function(){ return i; }); } return (scopes[0]() === "a" && scopes[1]() === "b");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§temporal dead zone (strict mode)
?
function(){
'use strict'; var passed = (function(){ try { qux; } catch(e) { return true; }}()); function fn() { passed &= qux === 456; } const qux = 456; fn(); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag

let

§basic support
?
function(){
let foo = 123; return (foo === 123);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Flag
§is block-scoped
?
function(){
let bar = 123; { let bar = 456; } return bar === 123;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Flag
§scope shadow resolution
?
function(){
try { { let bar = 456; } let bar = 123; return bar === 123; } catch(e) { return false; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
No
Error
No
No
§cannot be in statements
?
function(){
let bar = 1; try { Function("if(true) let baz = 1;")(); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Flag
§for loop statement scope
?
function(){
let baz = 1; for(let baz = 0; false;) {} return baz === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Flag
§temporal dead zone
?
function(){
var passed = (function(){ try { qux; } catch(e) { return true; }}()); function fn() { passed &= qux === 456; } let qux = 456; fn(); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Flag
§for/for-in loop iteration scope
?
function(){
let scopes = []; for(let i = 0; i < 2; i++) { scopes.push(function(){ return i; }); } let passed = (scopes[0]() === 0 && scopes[1]() === 1); scopes = []; for(let i in { a:1, b:1 }) { scopes.push(function(){ return i; }); } passed &= (scopes[0]() === "a" && scopes[1]() === "b"); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
No
§basic support (strict mode)
?
function(){
'use strict'; let foo = 123; return (foo === 123);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
§is block-scoped (strict mode)
?
function(){
'use strict'; let bar = 123; { let bar = 456; } return bar === 123;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
§scope shadow resolution (strict mode)
?
function(){
'use strict'; try { { let bar = 456; } let bar = 123; return bar === 123; } catch(e) { return false; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
§cannot be in statements (strict mode)
?
function(){
'use strict'; let bar = 1; try { Function("'use strict'; if(true) let baz = 1;")(); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
§for loop statement scope (strict mode)
?
function(){
'use strict'; let baz = 1; for(let baz = 0; false;) {} return baz === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
§temporal dead zone (strict mode)
?
function(){
'use strict'; var passed = (function(){ try { qux; } catch(e) { return true; }}()); function fn() { passed &= qux === 456; } let qux = 456; fn(); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
§for/for-in loop iteration scope (strict mode)
?
function(){
'use strict'; let scopes = []; for(let i = 0; i < 2; i++) { scopes.push(function(){ return i; }); } let passed = (scopes[0]() === 0 && scopes[1]() === 1); scopes = []; for(let i in { a:1, b:1 }) { scopes.push(function(){ return i; }); } passed &= (scopes[0]() === "a" && scopes[1]() === "b"); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
No

§block-level function declaration
?
function(){
'use strict'; if (f() !== 1) return false; function f() { return 1; } { if (f() !== 2) return false; function f() { return 2; } if (f() !== 2) return false; } if (f() !== 1) return false; return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag

functions

arrow functions

§0 parameters
?
function(){
return (() => 5)() === 5;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§1 parameter, no brackets
?
function(){
var b = x => x + "foo"; return (b("fee fie foe ") === "fee fie foe foo");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§multiple parameters
?
function(){
var c = (v, w, x, y, z) => "" + v + w + x + y + z; return (c(6, 5, 4, 3, 2) === "65432");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§lexical "this" binding
?
function(){
var d = { x : "bar", y : function() { return z => this.x + z; }}.y(); var e = { x : "baz", y : d }; return d("ley") === "barley" && e.y("ley") === "barley";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
Error
Error
§"this" unchanged by call or apply
?
function(){
var d = { x : "foo", y : function() { return () => this.x; }}; var e = { x : "bar" }; return d.y().call(e) === "foo" && d.y().apply(e) === "foo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
Error
Error
§can't be bound, can be curried
?
function(){
var d = { x : "bar", y : function() { return z => this.x + z; }}; var e = { x : "baz" }; return d.y().bind(e, "ley")() === "barley";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
Error
Error
§lexical "arguments" binding
?
function(){
var f = (function() { return z => arguments[0]; }(5)); return f(6) === 5;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
Error
Error
§no line break between params and =>
?
function(){
return (() => { try { Function("x\n => 2")(); } catch(e) { return true; } })();
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
Error
Error
§correct precedence
?
function(){
return (() => { try { Function("0 || () => 2")(); } catch(e) { return true; } })();
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Error
No
Error
Error
§no "prototype" property
?
function(){
var a = () => 5; return !a.hasOwnProperty("prototype");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
Error
Error
§lexical "super" binding in constructors
?
function(){
var received; class B { constructor (arg) { received = arg; } } class C extends B { constructor () { var callSuper = () => super('foo'); callSuper(); } } return new C instanceof C && received === 'foo'
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§lexical "super" binding in methods
?
function(){
class B { qux() { return "quux"; } } class C extends B { baz() { return x => super.qux(); } } var arrow = new C().baz(); return arrow() === "quux";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§lexical "new.target" binding
?
function(){
function C() { return x => new.target; } return new C()() === C && C()() === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error

class

§class statement
?
function(){
class C {} return typeof C === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§is block-scoped
?
function(){
class C {} var c1 = C; { class C {} var c2 = C; } return C === c1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§class expression
?
function(){
return typeof class C {} === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§anonymous class
?
function(){
return typeof class {} === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§constructor
?
function(){
class C { constructor() { this.x = 1; } } return C.prototype.constructor === C && new C().x === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§prototype methods
?
function(){
class C { method() { return 2; } } return typeof C.prototype.method === "function" && new C().method() === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§string-keyed methods
?
function(){
class C { "foo bar"() { return 2; } } return typeof C.prototype["foo bar"] === "function" && new C()["foo bar"]() === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§computed prototype methods
?
function(){
var foo = "method"; class C { [foo]() { return 2; } } return typeof C.prototype.method === "function" && new C().method() === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§optional semicolons
?
function(){
class C { ; method() { return 2; }; method2() { return 2; } method3() { return 2; }; } return typeof C.prototype.method === "function" && typeof C.prototype.method2 === "function" && typeof C.prototype.method3 === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§static methods
?
function(){
class C { static method() { return 3; } } return typeof C.method === "function" && C.method() === 3;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§computed static methods
?
function(){
var foo = "method"; class C { static [foo]() { return 3; } } return typeof C.method === "function" && C.method() === 3;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§accessor properties
?
function(){
var baz = false; class C { get foo() { return "foo"; } set bar(x) { baz = x; } } new C().bar = true; return new C().foo === "foo" && baz;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§computed accessor properties
?
function(){
var garply = "foo", grault = "bar", baz = false; class C { get [garply]() { return "foo"; } set [grault](x) { baz = x; } } new C().bar = true; return new C().foo === "foo" && baz;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§static accessor properties
?
function(){
var baz = false; class C { static get foo() { return "foo"; } static set bar(x) { baz = x; } } C.bar = true; return C.foo === "foo" && baz;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§computed static accessor properties
?
function(){
var garply = "foo", grault = "bar", baz = false; class C { static get [garply]() { return "foo"; } static set [grault](x) { baz = x; } } C.bar = true; return C.foo === "foo" && baz;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§class name is lexically scoped
?
function(){
class C { method() { return typeof C === "function"; } } var M = C.prototype.method; C = undefined; return C === undefined && M();
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§computed names, temporal dead zone
?
function(){
try { var B = class C { [C](){} } } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§methods aren't enumerable
?
function(){
class C { foo() {} static bar() {} } return !C.prototype.propertyIsEnumerable("foo") && !C.propertyIsEnumerable("bar");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§implicit strict mode
?
function(){
class C { static method() { return this === undefined; } } return (0,C.method)();
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§constructor requires new
?
function(){
class C {} try { C(); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§extends
?
function(){
class B {} class C extends B {} return new C() instanceof B && B.isPrototypeOf(C);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§extends expressions
?
function(){
var B; class C extends (B = class {}) {} return new C() instanceof B && B.isPrototypeOf(C);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§extends null
?
function(){
class C extends null { constructor() { return Object.create(null); } } return Function.prototype.isPrototypeOf(C) && Object.getPrototypeOf(C.prototype) === null;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§new.target
?
function(){
var passed = false; new function f() { passed = new.target === f; }(); class A { constructor() { passed &= new.target === B; } } class B extends A {} new B(); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error

super

§statement in constructors
?
function(){
var passed = false; class B { constructor(a) { passed = (a === "barbaz"); } } class C extends B { constructor(a) { super("bar" + a); } } new C("baz"); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§expression in constructors
?
function(){
class B { constructor(a) { return ["foo" + a]; } } class C extends B { constructor(a) { return super("bar" + a); } } return new C("baz")[0] === "foobarbaz";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§in methods, property access
?
function(){
class B {} B.prototype.qux = "foo"; B.prototype.corge = "baz"; class C extends B { quux(a) { return super.qux + a + super["corge"]; } } C.prototype.qux = "garply"; return new C().quux("bar") === "foobarbaz";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§in methods, method calls
?
function(){
class B { qux(a) { return "foo" + a; } } class C extends B { qux(a) { return super.qux("bar" + a); } } return new C().qux("baz") === "foobarbaz";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§method calls use correct "this" binding
?
function(){
class B { qux(a) { return this.foo + a; } } class C extends B { qux(a) { return super.qux("bar" + a); } } var obj = new C(); obj.foo = "foo"; return obj.qux("baz") === "foobarbaz";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§constructor calls use correct "new.target" binding
?
function(){
var passed; class B { constructor() { passed = (new.target === C); } } class C extends B { constructor() { super(); } } new C(); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§is statically bound
?
function(){
class B { qux() { return "bar"; } } class C extends B { qux() { return super.qux() + this.corge; } } var obj = { qux: C.prototype.qux, corge: "ley" }; return obj.qux() === "barley";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§super() invokes the correct constructor
?
function(){
// checks that super() is *not* a synonym of super.constructor() var passed; class B { constructor() { passed = true; } }; B.prototype.constructor = function () { passed = false; }; class C extends B { }; new C; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error

generators

§basic functionality
?
function(){
function * generator(){ yield 5; yield 6; }; var iterator = generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§generator function expressions
?
function(){
var generator = function * (){ yield 5; yield 6; }; var iterator = generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§correct "this" binding
?
function(){
function * generator(){ yield this.x; yield this.y; }; var iterator = { g: generator, x: 5, y: 6 }.g(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§can't use "this" with new
?
function(){
function * generator(){ yield this.x; yield this.y; }; try { (new generator()).next(); } catch (e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Error
No
Error
Error
§sending
?
function(){
var sent; function * generator(){ sent = [yield 5, yield 6]; }; var iterator = generator(); iterator.next(); iterator.next("foo"); iterator.next("bar"); return sent[0] === "foo" && sent[1] === "bar";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§%GeneratorPrototype%
?
function(){
function * generatorFn(){} var ownProto = Object.getPrototypeOf(generatorFn()); var passed = ownProto === generatorFn.prototype; var sharedProto = Object.getPrototypeOf(ownProto); passed &= sharedProto !== Object.prototype && sharedProto === Object.getPrototypeOf(function*(){}.prototype) && sharedProto.hasOwnProperty('next'); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§%GeneratorPrototype% prototype chain
?
function(){
function * generatorFn(){} var g = generatorFn(); var ownProto = Object.getPrototypeOf(g); var passed = ownProto === generatorFn.prototype; var sharedProto = Object.getPrototypeOf(ownProto); var iterProto = Object.getPrototypeOf(sharedProto); passed &= iterProto.hasOwnProperty(Symbol.iterator) && !sharedProto .hasOwnProperty(Symbol.iterator) && !ownProto .hasOwnProperty(Symbol.iterator) && g[Symbol.iterator]() === g; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
Error
Error
§%GeneratorPrototype%.constructor
?
function(){
function * g (){} var iterator = new g.constructor("a","b","c","yield a; yield b; yield c;")(5,6,7); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === 7 && item.done === false; item = iterator.next(); passed &= item.value === undefined && item.done === true; passed &= g.constructor === (function*(){}).constructor; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§%GeneratorPrototype%.throw
?
function(){
var passed = false; function * generator(){ try { yield 5; yield 6; } catch(e) { passed = (e === "foo"); } }; var iterator = generator(); iterator.next(); iterator.throw("foo"); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§%GeneratorPrototype%.return
?
function(){
function * generator(){ yield 5; yield 6; }; var iterator = generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.return("quxquux"); passed &= item.value === "quxquux" && item.done === true; item = iterator.next(); passed &= item.value === undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§yield operator precedence
?
function(){
var passed; function * generator(){ passed = yield 0 ? true : false; }; var iterator = generator(); iterator.next(); iterator.next(true); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§yield *, arrays
?
function(){
var iterator = (function * generator() { yield * [5, 6]; }()); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§yield *, sparse arrays
?
function(){
var iterator = (function * generator() { yield * [,,]; }()); var item = iterator.next(); var passed = item.value === undefined && item.done === false; item = iterator.next(); passed &= item.value === undefined && item.done === false; item = iterator.next(); passed &= item.value === undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§yield *, strings
?
function(){
var iterator = (function * generator() { yield * "56"; }()); var item = iterator.next(); var passed = item.value === "5" && item.done === false; item = iterator.next(); passed &= item.value === "6" && item.done === false; item = iterator.next(); passed &= item.value === undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§yield *, astral plane strings
?
function(){
var iterator = (function * generator() { yield * "𠮷𠮶"; }()); var item = iterator.next(); var passed = item.value === "𠮷" && item.done === false; item = iterator.next(); passed &= item.value === "𠮶" && item.done === false; item = iterator.next(); passed &= item.value === undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§yield *, generator instances
?
function(){
var iterator = (function * generator() { yield * (function*(){ yield 5; yield 6; yield 7; }()); }()); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === 7 && item.done === false; item = iterator.next(); passed &= item.value === undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§yield *, generic iterables
?
function(){
var iterator = (function * generator() { yield * global.__createIterableObject([5, 6, 7]); }()); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === 7 && item.done === false; item = iterator.next(); passed &= item.value === undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§yield *, instances of iterables
?
function(){
var iterator = (function * generator() { yield * Object.create(__createIterableObject([5, 6, 7])); }()); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === 7 && item.done === false; item = iterator.next(); passed &= item.value === undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§yield * on non-iterables is a runtime error
?
function(){
var iterator = (function * generator() { yield * [5]; }()); var item = iterator.next(); var passed = item.value === 5 && item.done === false; iterator = (function * generator() { yield * 5; }()); try { iterator.next(); } catch (e) { return passed; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
§yield *, iterator closing
?
function(){
var closed = ''; var iter = __createIterableObject([1, 2, 3], { 'return': function(){ closed += 'a'; return {done: true}; } }); var gen = (function* generator(){ try { yield *iter; } finally { closed += 'b'; } })(); gen.next(); gen['return'](); return closed === 'ab';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§yield *, iterator closing via throw()
?
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'throw': undefined, 'return': function() { closed = true; return {done: true}; } }); var gen = (function*(){ try { yield *iter; } catch(e){} })(); gen.next(); gen['throw'](); return closed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Error
No
Error
Error
§shorthand generator methods
?
function(){
var o = { * generator() { yield 5; yield 6; }, }; var iterator = o.generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§string-keyed shorthand generator methods
?
function(){
var o = { * "foo bar"() { yield 5; yield 6; }, }; var iterator = o["foo bar"](); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§computed shorthand generators
?
function(){
var garply = "generator"; var o = { * [garply] () { yield 5; yield 6; }, }; var iterator = o.generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§shorthand generator methods, classes
?
function(){
class C { * generator() { yield 5; yield 6; } }; var iterator = new C().generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§computed shorthand generators, classes
?
function(){
var garply = "generator"; class C { * [garply] () { yield 5; yield 6; } } var iterator = new C().generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§shorthand generators can't be constructors
?
function(){
class C { * generator() { yield 5; yield 6; } }; try { Function("class D { * constructor() { return {}; } }"); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error

built-ins

typed arrays

§Int8Array
?
function(){
var buffer = new ArrayBuffer(64); var view = new Int8Array(buffer); view[0] = 0x80; return view[0] === -0x80;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§Uint8Array
?
function(){
var buffer = new ArrayBuffer(64); var view = new Uint8Array(buffer); view[0] = 0x100; return view[0] === 0;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§Uint8ClampedArray
?
function(){
var buffer = new ArrayBuffer(64); var view = new Uint8ClampedArray(buffer); view[0] = 0x100; return view[0] === 0xFF;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§Int16Array
?
function(){
var buffer = new ArrayBuffer(64); var view = new Int16Array(buffer); view[0] = 0x8000; return view[0] === -0x8000;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§Uint16Array
?
function(){
var buffer = new ArrayBuffer(64); var view = new Uint16Array(buffer); view[0] = 0x10000; return view[0] === 0;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§Int32Array
?
function(){
var buffer = new ArrayBuffer(64); var view = new Int32Array(buffer); view[0] = 0x80000000; return view[0] === -0x80000000;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§Uint32Array
?
function(){
var buffer = new ArrayBuffer(64); var view = new Uint32Array(buffer); view[0] = 0x100000000; return view[0] === 0;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§Float32Array
?
function(){
var buffer = new ArrayBuffer(64); var view = new Float32Array(buffer); view[0] = 0.1; return view[0] === 0.10000000149011612;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§Float64Array
?
function(){
var buffer = new ArrayBuffer(64); var view = new Float64Array(buffer); view[0] = 0.1; return view[0] === 0.1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§DataView (Int8)
?
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setInt8 (0, 0x80); return view.getInt8(0) === -0x80;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§DataView (Uint8)
?
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setUint8(0, 0x100); return view.getUint8(0) === 0;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§DataView (Int16)
?
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setInt16(0, 0x8000); return view.getInt16(0) === -0x8000;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§DataView (Uint16)
?
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setUint16(0, 0x10000); return view.getUint16(0) === 0;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§DataView (Int32)
?
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setInt32(0, 0x80000000); return view.getInt32(0) === -0x80000000;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§DataView (Uint32)
?
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setUint32(0, 0x100000000); return view.getUint32(0) === 0;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§DataView (Float32)
?
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setFloat32(0, 0.1); return view.getFloat32(0) === 0.10000000149011612;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§DataView (Float64)
?
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setFloat64(0, 0.1); return view.getFloat64(0) === 0.1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§ArrayBuffer[Symbol.species]
?
function(){
return typeof ArrayBuffer[Symbol.species] === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
Error
Error
§constructors require new
?
function(){
var buffer = new ArrayBuffer(64); var constructors = [ 'ArrayBuffer', 'DataView', 'Int8Array', 'Uint8Array', 'Uint8ClampedArray', 'Int16Array', 'Uint16Array', 'Int32Array', 'Uint32Array', 'Float32Array', 'Float64Array' ]; return constructors.every(function (constructor) { try { if (constructor in global) { global[constructor](constructor === "ArrayBuffer" ? 64 : buffer); } return false; } catch(e) { return true; } });
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§constructors accept generic iterables
?
function(){
var constructors = [ 'Int8Array', 'Uint8Array', 'Uint8ClampedArray', 'Int16Array', 'Uint16Array', 'Int32Array', 'Uint32Array', 'Float32Array', 'Float64Array' ]; for(var i = 0; i < constructors.length; i++){ var arr = new global[constructors[i]](__createIterableObject([1, 2, 3])); if(arr.length !== 3 || arr[0] !== 1 || arr[1] !== 2 || arr[2] !== 3)return false; } return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§correct prototype chains
?
function(){
var constructors = [ 'Int8Array', 'Uint8Array', 'Uint8ClampedArray', 'Int16Array', 'Uint16Array', 'Int32Array', 'Uint32Array', 'Float32Array', 'Float64Array' ]; var constructor = Object.getPrototypeOf(Int8Array); var prototype = Object.getPrototypeOf(Int8Array.prototype); if(constructor === Function.prototype || prototype === Object.prototype)return false; for(var i = 0; i < constructors.length; i+=1) { if (!(constructors[i] in global && Object.getPrototypeOf(global[constructors[i]]) === constructor && Object.getPrototypeOf(global[constructors[i]].prototype) === prototype && Object.getOwnPropertyNames(global[constructors[i]].prototype).sort() + '' === "BYTES_PER_ELEMENT,constructor")) { return false; } } return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
§%TypedArray%.from
?
function(){
return typeof Int8Array.from === "function" && typeof Uint8Array.from === "function" && typeof Uint8ClampedArray.from === "function" && typeof Int16Array.from === "function" && typeof Uint16Array.from === "function" && typeof Int32Array.from === "function" && typeof Uint32Array.from === "function" && typeof Float32Array.from === "function" && typeof Float64Array.from === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§%TypedArray%.of
?
function(){
return typeof Int8Array.of === "function" && typeof Uint8Array.of === "function" && typeof Uint8ClampedArray.of === "function" && typeof Int16Array.of === "function" && typeof Uint16Array.of === "function" && typeof Int32Array.of === "function" && typeof Uint32Array.of === "function" && typeof Float32Array.of === "function" && typeof Float64Array.of === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§%TypedArray%.prototype.subarray
?
function(){
return typeof Int8Array.prototype.subarray === "function" && typeof Uint8Array.prototype.subarray === "function" && typeof Uint8ClampedArray.prototype.subarray === "function" && typeof Int16Array.prototype.subarray === "function" && typeof Uint16Array.prototype.subarray === "function" && typeof Int32Array.prototype.subarray === "function" && typeof Uint32Array.prototype.subarray === "function" && typeof Float32Array.prototype.subarray === "function" && typeof Float64Array.prototype.subarray === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§%TypedArray%.prototype.join
?
function(){
return typeof Int8Array.prototype.join === "function" && typeof Uint8Array.prototype.join === "function" && typeof Uint8ClampedArray.prototype.join === "function" && typeof Int16Array.prototype.join === "function" && typeof Uint16Array.prototype.join === "function" && typeof Int32Array.prototype.join === "function" && typeof Uint32Array.prototype.join === "function" && typeof Float32Array.prototype.join === "function" && typeof Float64Array.prototype.join === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§%TypedArray%.prototype.indexOf
?
function(){
return typeof Int8Array.prototype.indexOf === "function" && typeof Uint8Array.prototype.indexOf === "function" && typeof Uint8ClampedArray.prototype.indexOf === "function" && typeof Int16Array.prototype.indexOf === "function" && typeof Uint16Array.prototype.indexOf === "function" && typeof Int32Array.prototype.indexOf === "function" && typeof Uint32Array.prototype.indexOf === "function" && typeof Float32Array.prototype.indexOf === "function" && typeof Float64Array.prototype.indexOf === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§%TypedArray%.prototype.lastIndexOf
?
function(){
return typeof Int8Array.prototype.lastIndexOf === "function" && typeof Uint8Array.prototype.lastIndexOf === "function" && typeof Uint8ClampedArray.prototype.lastIndexOf === "function" && typeof Int16Array.prototype.lastIndexOf === "function" && typeof Uint16Array.prototype.lastIndexOf === "function" && typeof Int32Array.prototype.lastIndexOf === "function" && typeof Uint32Array.prototype.lastIndexOf === "function" && typeof Float32Array.prototype.lastIndexOf === "function" && typeof Float64Array.prototype.lastIndexOf === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§%TypedArray%.prototype.slice
?
function(){
return typeof Int8Array.prototype.slice === "function" && typeof Uint8Array.prototype.slice === "function" && typeof Uint8ClampedArray.prototype.slice === "function" && typeof Int16Array.prototype.slice === "function" && typeof Uint16Array.prototype.slice === "function" && typeof Int32Array.prototype.slice === "function" && typeof Uint32Array.prototype.slice === "function" && typeof Float32Array.prototype.slice === "function" && typeof Float64Array.prototype.slice === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§%TypedArray%.prototype.every
?
function(){
return typeof Int8Array.prototype.every === "function" && typeof Uint8Array.prototype.every === "function" && typeof Uint8ClampedArray.prototype.every === "function" && typeof Int16Array.prototype.every === "function" && typeof Uint16Array.prototype.every === "function" && typeof Int32Array.prototype.every === "function" && typeof Uint32Array.prototype.every === "function" && typeof Float32Array.prototype.every === "function" && typeof Float64Array.prototype.every === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§%TypedArray%.prototype.filter
?
function(){
return typeof Int8Array.prototype.filter === "function" && typeof Uint8Array.prototype.filter === "function" && typeof Uint8ClampedArray.prototype.filter === "function" && typeof Int16Array.prototype.filter === "function" && typeof Uint16Array.prototype.filter === "function" && typeof Int32Array.prototype.filter === "function" && typeof Uint32Array.prototype.filter === "function" && typeof Float32Array.prototype.filter === "function" && typeof Float64Array.prototype.filter === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§%TypedArray%.prototype.forEach
?
function(){
return typeof Int8Array.prototype.forEach === "function" && typeof Uint8Array.prototype.forEach === "function" && typeof Uint8ClampedArray.prototype.forEach === "function" && typeof Int16Array.prototype.forEach === "function" && typeof Uint16Array.prototype.forEach === "function" && typeof Int32Array.prototype.forEach === "function" && typeof Uint32Array.prototype.forEach === "function" && typeof Float32Array.prototype.forEach === "function" && typeof Float64Array.prototype.forEach === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§%TypedArray%.prototype.map
?
function(){
return typeof Int8Array.prototype.map === "function" && typeof Uint8Array.prototype.map === "function" && typeof Uint8ClampedArray.prototype.map === "function" && typeof Int16Array.prototype.map === "function" && typeof Uint16Array.prototype.map === "function" && typeof Int32Array.prototype.map === "function" && typeof Uint32Array.prototype.map === "function" && typeof Float32Array.prototype.map === "function" && typeof Float64Array.prototype.map === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§%TypedArray%.prototype.reduce
?
function(){
return typeof Int8Array.prototype.reduce === "function" && typeof Uint8Array.prototype.reduce === "function" && typeof Uint8ClampedArray.prototype.reduce === "function" && typeof Int16Array.prototype.reduce === "function" && typeof Uint16Array.prototype.reduce === "function" && typeof Int32Array.prototype.reduce === "function" && typeof Uint32Array.prototype.reduce === "function" && typeof Float32Array.prototype.reduce === "function" && typeof Float64Array.prototype.reduce === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§%TypedArray%.prototype.reduceRight
?
function(){
return typeof Int8Array.prototype.reduceRight === "function" && typeof Uint8Array.prototype.reduceRight === "function" && typeof Uint8ClampedArray.prototype.reduceRight === "function" && typeof Int16Array.prototype.reduceRight === "function" && typeof Uint16Array.prototype.reduceRight === "function" && typeof Int32Array.prototype.reduceRight === "function" && typeof Uint32Array.prototype.reduceRight === "function" && typeof Float32Array.prototype.reduceRight === "function" && typeof Float64Array.prototype.reduceRight === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§%TypedArray%.prototype.reverse
?
function(){
return typeof Int8Array.prototype.reverse === "function" && typeof Uint8Array.prototype.reverse === "function" && typeof Uint8ClampedArray.prototype.reverse === "function" && typeof Int16Array.prototype.reverse === "function" && typeof Uint16Array.prototype.reverse === "function" && typeof Int32Array.prototype.reverse === "function" && typeof Uint32Array.prototype.reverse === "function" && typeof Float32Array.prototype.reverse === "function" && typeof Float64Array.prototype.reverse === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§%TypedArray%.prototype.some
?
function(){
return typeof Int8Array.prototype.some === "function" && typeof Uint8Array.prototype.some === "function" && typeof Uint8ClampedArray.prototype.some === "function" && typeof Int16Array.prototype.some === "function" && typeof Uint16Array.prototype.some === "function" && typeof Int32Array.prototype.some === "function" && typeof Uint32Array.prototype.some === "function" && typeof Float32Array.prototype.some === "function" && typeof Float64Array.prototype.some === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§%TypedArray%.prototype.sort
?
function(){
return typeof Int8Array.prototype.sort === "function" && typeof Uint8Array.prototype.sort === "function" && typeof Uint8ClampedArray.prototype.sort === "function" && typeof Int16Array.prototype.sort === "function" && typeof Uint16Array.prototype.sort === "function" && typeof Int32Array.prototype.sort === "function" && typeof Uint32Array.prototype.sort === "function" && typeof Float32Array.prototype.sort === "function" && typeof Float64Array.prototype.sort === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§%TypedArray%.prototype.copyWithin
?
function(){
return typeof Int8Array.prototype.copyWithin === "function" && typeof Uint8Array.prototype.copyWithin === "function" && typeof Uint8ClampedArray.prototype.copyWithin === "function" && typeof Int16Array.prototype.copyWithin === "function" && typeof Uint16Array.prototype.copyWithin === "function" && typeof Int32Array.prototype.copyWithin === "function" && typeof Uint32Array.prototype.copyWithin === "function" && typeof Float32Array.prototype.copyWithin === "function" && typeof Float64Array.prototype.copyWithin === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§%TypedArray%.prototype.find
?
function(){
return typeof Int8Array.prototype.find === "function" && typeof Uint8Array.prototype.find === "function" && typeof Uint8ClampedArray.prototype.find === "function" && typeof Int16Array.prototype.find === "function" && typeof Uint16Array.prototype.find === "function" && typeof Int32Array.prototype.find === "function" && typeof Uint32Array.prototype.find === "function" && typeof Float32Array.prototype.find === "function" && typeof Float64Array.prototype.find === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§%TypedArray%.prototype.findIndex
?
function(){
return typeof Int8Array.prototype.findIndex === "function" && typeof Uint8Array.prototype.findIndex === "function" && typeof Uint8ClampedArray.prototype.findIndex === "function" && typeof Int16Array.prototype.findIndex === "function" && typeof Uint16Array.prototype.findIndex === "function" && typeof Int32Array.prototype.findIndex === "function" && typeof Uint32Array.prototype.findIndex === "function" && typeof Float32Array.prototype.findIndex === "function" && typeof Float64Array.prototype.findIndex === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§%TypedArray%.prototype.fill
?
function(){
return typeof Int8Array.prototype.fill === "function" && typeof Uint8Array.prototype.fill === "function" && typeof Uint8ClampedArray.prototype.fill === "function" && typeof Int16Array.prototype.fill === "function" && typeof Uint16Array.prototype.fill === "function" && typeof Int32Array.prototype.fill === "function" && typeof Uint32Array.prototype.fill === "function" && typeof Float32Array.prototype.fill === "function" && typeof Float64Array.prototype.fill === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§%TypedArray%.prototype.keys
?
function(){
return typeof Int8Array.prototype.keys === "function" && typeof Uint8Array.prototype.keys === "function" && typeof Uint8ClampedArray.prototype.keys === "function" && typeof Int16Array.prototype.keys === "function" && typeof Uint16Array.prototype.keys === "function" && typeof Int32Array.prototype.keys === "function" && typeof Uint32Array.prototype.keys === "function" && typeof Float32Array.prototype.keys === "function" && typeof Float64Array.prototype.keys === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§%TypedArray%.prototype.values
?
function(){
return typeof Int8Array.prototype.values === "function" && typeof Uint8Array.prototype.values === "function" && typeof Uint8ClampedArray.prototype.values === "function" && typeof Int16Array.prototype.values === "function" && typeof Uint16Array.prototype.values === "function" && typeof Int32Array.prototype.values === "function" && typeof Uint32Array.prototype.values === "function" && typeof Float32Array.prototype.values === "function" && typeof Float64Array.prototype.values === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§%TypedArray%.prototype.entries
?
function(){
return typeof Int8Array.prototype.entries === "function" && typeof Uint8Array.prototype.entries === "function" && typeof Uint8ClampedArray.prototype.entries === "function" && typeof Int16Array.prototype.entries === "function" && typeof Uint16Array.prototype.entries === "function" && typeof Int32Array.prototype.entries === "function" && typeof Uint32Array.prototype.entries === "function" && typeof Float32Array.prototype.entries === "function" && typeof Float64Array.prototype.entries === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§%TypedArray%.prototype[Symbol.iterator]
?
function(){
return typeof Int8Array.prototype[Symbol.iterator] === "function" && typeof Uint8Array.prototype[Symbol.iterator] === "function" && typeof Uint8ClampedArray.prototype[Symbol.iterator] === "function" && typeof Int16Array.prototype[Symbol.iterator] === "function" && typeof Uint16Array.prototype[Symbol.iterator] === "function" && typeof Int32Array.prototype[Symbol.iterator] === "function" && typeof Uint32Array.prototype[Symbol.iterator] === "function" && typeof Float32Array.prototype[Symbol.iterator] === "function" && typeof Float64Array.prototype[Symbol.iterator] === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§%TypedArray%[Symbol.species]
?
function(){
return typeof Int8Array[Symbol.species] === "function" && typeof Uint8Array[Symbol.species] === "function" && typeof Uint8ClampedArray[Symbol.species] === "function" && typeof Int16Array[Symbol.species] === "function" && typeof Uint16Array[Symbol.species] === "function" && typeof Int32Array[Symbol.species] === "function" && typeof Uint32Array[Symbol.species] === "function" && typeof Float32Array[Symbol.species] === "function" && typeof Float64Array[Symbol.species] === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
Error
Error

Map

§basic functionality
?
function(){
var key = {}; var map = new Map(); map.set(key, 123); return map.has(key) && map.get(key) === 123;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
§constructor arguments
?
function(){
var key1 = {}; var key2 = {}; var map = new Map([[key1, 123], [key2, 456]]); return map.has(key1) && map.get(key1) === 123 && map.has(key2) && map.get(key2) === 456;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§constructor requires new
?
function(){
new Map(); try { Map(); return false; } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§constructor accepts null
?
function(){
new Map(null); return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
§constructor invokes set
?
function(){
var passed = false; var _set = Map.prototype.set; Map.prototype.set = function(k, v) { passed = true; }; new Map([ [1, 2] ]); Map.prototype.set = _set; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§iterator closing
?
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); try { new Map(iter); } catch(e){} return closed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
§Map.prototype.set returns this
?
function(){
var map = new Map(); return map.set(0, 0) === map;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§-0 key converts to +0
?
function(){
var map = new Map(); map.set(-0, "foo"); var k; map.forEach(function (value, key) { k = 1 / key; }); return k === Infinity && map.get(+0) == "foo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error
§Map.prototype.size
?
function(){
var key = {}; var map = new Map(); map.set(key, 123); return map.size === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§Map.prototype.delete
?
function(){
return typeof Map.prototype.delete === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
§Map.prototype.clear
?
function(){
return typeof Map.prototype.clear === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§Map.prototype.forEach
?
function(){
return typeof Map.prototype.forEach === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§Map.prototype.keys
?
function(){
return typeof Map.prototype.keys === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§Map.prototype.values
?
function(){
return typeof Map.prototype.values === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§Map.prototype.entries
?
function(){
return typeof Map.prototype.entries === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§Map.prototype[Symbol.iterator]
?
function(){
return typeof Map.prototype[Symbol.iterator] === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§Map.prototype isn't an instance
?
function(){
new Map(); var obj = {}; try { Map.prototype.has(obj); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
§Map iterator prototype chain
?
function(){
// Iterator instance var iterator = new Map()[Symbol.iterator](); // %MapIteratorPrototype% var proto1 = Object.getPrototypeOf(iterator); // %IteratorPrototype% var proto2 = Object.getPrototypeOf(proto1); return proto2.hasOwnProperty(Symbol.iterator) && !proto1 .hasOwnProperty(Symbol.iterator) && !iterator .hasOwnProperty(Symbol.iterator) && iterator[Symbol.iterator]() === iterator;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error
§Map[Symbol.species]
?
function(){
var prop = Object.getOwnPropertyDescriptor(Map, Symbol.species); return 'get' in prop && Map[Symbol.species] === Map;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error

Set

§basic functionality
?
function(){
var obj = {}; var set = new Set(); set.add(123); set.add(123); return set.has(123);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
§constructor arguments
?
function(){
var obj1 = {}; var obj2 = {}; var set = new Set([obj1, obj2]); return set.has(obj1) && set.has(obj2);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§constructor requires new
?
function(){
new Set(); try { Set(); return false; } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§constructor accepts null
?
function(){
new Set(null); return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
§constructor invokes add
?
function(){
var passed = false; var _add = Set.prototype.add; Set.prototype.add = function(v) { passed = true; }; new Set([1]); Set.prototype.add = _add; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§iterator closing
?
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); var add = Set.prototype.add; Set.prototype.add = function(){ throw 0 }; try { new Set(iter); } catch(e){} Set.prototype.add = add; return closed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
Error
No
§Set.prototype.add returns this
?
function(){
var set = new Set(); return set.add(0) === set;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§-0 key converts to +0
?
function(){
var set = new Set(); set.add(-0); var k; set.forEach(function (value) { k = 1 / value; }); return k === Infinity && set.has(+0);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error
§Set.prototype.size
?
function(){
var obj = {}; var set = new Set(); set.add(123); set.add(123); set.add(456); return set.size === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§Set.prototype.delete
?
function(){
return typeof Set.prototype.delete === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
§Set.prototype.clear
?
function(){
return typeof Set.prototype.clear === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§Set.prototype.forEach
?
function(){
return typeof Set.prototype.forEach === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§Set.prototype.keys
?
function(){
return typeof Set.prototype.keys === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§Set.prototype.values
?
function(){
return typeof Set.prototype.values === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§Set.prototype.entries
?
function(){
return typeof Set.prototype.entries === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§Set.prototype[Symbol.iterator]
?
function(){
return typeof Set.prototype[Symbol.iterator] === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§Set.prototype isn't an instance
?
function(){
new Set(); var obj = {}; try { Set.prototype.has(obj); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
§Set iterator prototype chain
?
function(){
// Iterator instance var iterator = new Set()[Symbol.iterator](); // %SetIteratorPrototype% var proto1 = Object.getPrototypeOf(iterator); // %IteratorPrototype% var proto2 = Object.getPrototypeOf(proto1); return proto2.hasOwnProperty(Symbol.iterator) && !proto1 .hasOwnProperty(Symbol.iterator) && !iterator .hasOwnProperty(Symbol.iterator) && iterator[Symbol.iterator]() === iterator;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error
§Set[Symbol.species]
?
function(){
var prop = Object.getOwnPropertyDescriptor(Set, Symbol.species); return 'get' in prop && Set[Symbol.species] === Set;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error

WeakMap

§basic functionality
?
function(){
var key = {}; var weakmap = new WeakMap(); weakmap.set(key, 123); return weakmap.has(key) && weakmap.get(key) === 123;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
§constructor arguments
?
function(){
var key1 = {}; var key2 = {}; var weakmap = new WeakMap([[key1, 123], [key2, 456]]); return weakmap.has(key1) && weakmap.get(key1) === 123 && weakmap.has(key2) && weakmap.get(key2) === 456;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§constructor requires new
?
function(){
new WeakMap(); try { WeakMap(); return false; } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§constructor accepts null
?
function(){
new WeakMap(null); return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
§constructor invokes set
?
function(){
var passed = false; var _set = WeakMap.prototype.set; WeakMap.prototype.set = function(k, v) { passed = true; }; new WeakMap([ [{ }, 42] ]); WeakMap.prototype.set = _set; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§frozen objects as keys
?
function(){
var f = Object.freeze({}); var m = new WeakMap; m.set(f, 42); return m.get(f) === 42;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
§iterator closing
?
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); try { new WeakMap(iter); } catch(e){} return closed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
§WeakMap.prototype.set returns this
?
function(){
var weakmap = new WeakMap(); var key = {}; return weakmap.set(key, 0) === weakmap;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
§WeakMap.prototype.delete
?
function(){
return typeof WeakMap.prototype.delete === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
§no WeakMap.prototype.clear method
?
function(){
if (!("clear" in WeakMap.prototype)) { return true; } var m = new WeakMap(); var key = {}; m.set(key, 2); m.clear(); return m.has(key);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Flag
§.has, .get and .delete methods accept primitives
?
function(){
var m = new WeakMap; return m.has(1) === false && m.get(1) === undefined && m.delete(1) === false;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§WeakMap.prototype isn't an instance
?
function(){
new WeakMap(); var obj = {}; try { WeakMap.prototype.has(obj); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag

WeakSet

§basic functionality
?
function(){
var obj1 = {}; var weakset = new WeakSet(); weakset.add(obj1); weakset.add(obj1); return weakset.has(obj1);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§constructor arguments
?
function(){
var obj1 = {}, obj2 = {}; var weakset = new WeakSet([obj1, obj2]); return weakset.has(obj1) && weakset.has(obj2);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§constructor requires new
?
function(){
new WeakSet(); try { WeakSet(); return false; } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§constructor accepts null
?
function(){
new WeakSet(null); return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§constructor invokes add
?
function(){
var passed = false; var _add = WeakSet.prototype.add; WeakSet.prototype.add = function(v) { passed = true; }; new WeakSet([ { } ]); WeakSet.prototype.add = _add; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§iterator closing
?
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); try { new WeakSet(iter); } catch(e){} return closed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
§WeakSet.prototype.add returns this
?
function(){
var weakset = new WeakSet(); var obj = {}; return weakset.add(obj) === weakset;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§WeakSet.prototype.delete
?
function(){
return typeof WeakSet.prototype.delete === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§no WeakSet.prototype.clear method
?
function(){
if (!("clear" in WeakSet.prototype)) { return true; } var s = new WeakSet(); var key = {}; s.add(key); s.clear(); return s.has(key);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error
§.has and .delete methods accept primitives
?
function(){
var s = new WeakSet; return s.has(1) === false && s.delete(1) === false;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§WeakSet.prototype isn't an instance
?
function(){
new WeakSet(); var obj = {}; try { WeakSet.prototype.has(obj); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error

Proxy

§constructor requires new
?
function(){
new Proxy({}, {}); try { Proxy({}, {}); return false; } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§no "prototype" property
?
function(){
new Proxy({}, {}); return !Proxy.hasOwnProperty('prototype');
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"get" handler
?
function(){
var proxied = { }; var proxy = new Proxy(proxied, { get: function (t, k, r) { return t === proxied && k === "foo" && r === proxy && 5; } }); return proxy.foo === 5;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"get" handler, instances of proxies
?
function(){
var proxied = { }; var proxy = Object.create(new Proxy(proxied, { get: function (t, k, r) { return t === proxied && k === "foo" && r === proxy && 5; } })); return proxy.foo === 5;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"get" handler invariants
?
function(){
var passed = false; var proxied = { }; var proxy = new Proxy(proxied, { get: function () { passed = true; return 4; } }); // The value reported for a property must be the same as the value of the corresponding // target object property if the target object property is a non-writable, // non-configurable own data property. Object.defineProperty(proxied, "foo", { value: 5, enumerable: true }); try { proxy.foo; return false; } catch(e) {} // The value reported for a property must be undefined if the corresponding target // object property is a non-configurable own accessor property that has undefined // as its [[Get]] attribute. Object.defineProperty(proxied, "bar", { set: function(){}, enumerable: true }); try { proxy.bar; return false; } catch(e) {} return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"set" handler
?
function(){
var proxied = { }; var passed = false; var proxy = new Proxy(proxied, { set: function (t, k, v, r) { passed = t === proxied && k + v === "foobar" && r === proxy; } }); proxy.foo = "bar"; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"set" handler, instances of proxies
?
function(){
var proxied = { }; var passed = false; var proxy = Object.create(new Proxy(proxied, { set: function (t, k, v, r) { passed = t === proxied && k + v === "foobar" && r === proxy; } })); proxy.foo = "bar"; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"set" handler invariants
?
function(){
var passed = false; new Proxy({},{}); // Cannot change the value of a property to be different from the value of // the corresponding target object if the corresponding target object // property is a non-writable, non-configurable own data property. var proxied = {}; var proxy = new Proxy(proxied, { set: function () { passed = true; return true; } }); Object.defineProperty(proxied, "foo", { value: 2, enumerable: true }); proxy.foo = 2; try { proxy.foo = 4; return false; } catch(e) {} // Cannot set the value of a property if the corresponding target // object property is a non-configurable own accessor property // that has undefined as its [[Set]] attribute. Object.defineProperty(proxied, "bar", { get: function(){}, enumerable: true }); try { proxy.bar = 2; return false; } catch(e) {} return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"has" handler
?
function(){
var proxied = {}; var passed = false; "foo" in new Proxy(proxied, { has: function (t, k) { passed = t === proxied && k === "foo"; } }); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"has" handler, instances of proxies
?
function(){
var proxied = {}; var passed = false; "foo" in Object.create(new Proxy(proxied, { has: function (t, k) { passed = t === proxied && k === "foo"; } })); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"has" handler invariants
?
function(){
var passed = false; new Proxy({},{}); // A property cannot be reported as non-existent, if it exists as a // non-configurable own property of the target object. var proxied = {}; var proxy = new Proxy(proxied, { has: function () { passed = true; return false; } }); Object.defineProperty(proxied, "foo", { value: 2, writable: true, enumerable: true }); try { 'foo' in proxy; return false; } catch(e) {} // A property cannot be reported as non-existent, if it exists as an // own property of the target object and the target object is not extensible. proxied.bar = 2; Object.preventExtensions(proxied); try { 'bar' in proxy; return false; } catch(e) {} return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"deleteProperty" handler
?
function(){
var proxied = {}; var passed = false; delete new Proxy(proxied, { deleteProperty: function (t, k) { passed = t === proxied && k === "foo"; } }).foo; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"deleteProperty" handler invariant
?
function(){
var passed = false; new Proxy({},{}); // A property cannot be reported as deleted, if it exists as a non-configurable // own property of the target object. var proxied = {}; Object.defineProperty(proxied, "foo", { value: 2, writable: true, enumerable: true }); try { delete new Proxy(proxied, { deleteProperty: function () { passed = true; return true; } }).foo; return false; } catch(e) {} return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"getOwnPropertyDescriptor" handler
?
function(){
var proxied = {}; var fakeDesc = { value: "foo", configurable: true }; var returnedDesc = Object.getOwnPropertyDescriptor( new Proxy(proxied, { getOwnPropertyDescriptor: function (t, k) { return t === proxied && k === "foo" && fakeDesc; } }), "foo" ); return (returnedDesc.value === fakeDesc.value && returnedDesc.configurable === fakeDesc.configurable && returnedDesc.writable === false && returnedDesc.enumerable === false);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"getOwnPropertyDescriptor" handler invariants
?
function(){
var passed = false; new Proxy({},{}); // A property cannot be reported as non-existent, if it exists as a non-configurable // own property of the target object. var proxied = {}; var proxy = new Proxy(proxied, { getOwnPropertyDescriptor: function () { passed = true; return undefined; } }); Object.defineProperty(proxied, "foo", { value: 2, writable: true, enumerable: true }); try { Object.getOwnPropertyDescriptor(proxy, "foo"); return false; } catch(e) {} // A property cannot be reported as non-existent, if it exists as an own property // of the target object and the target object is not extensible. proxied.bar = 3; Object.preventExtensions(proxied); try { Object.getOwnPropertyDescriptor(proxy, "bar"); return false; } catch(e) {} // A property cannot be reported as existent, if it does not exists as an own property // of the target object and the target object is not extensible. try { Object.getOwnPropertyDescriptor(new Proxy(proxied, { getOwnPropertyDescriptor: function() { return { value: 2, configurable: true, writable: true, enumerable: true }; }}), "baz"); return false; } catch(e) {} // A property cannot be reported as non-configurable, if it does not exists as an own // property of the target object or if it exists as a configurable own property of // the target object. try { Object.getOwnPropertyDescriptor(new Proxy({}, { getOwnPropertyDescriptor: function() { return { value: 2, configurable: false, writable: true, enumerable: true }; }}), "baz"); return false; } catch(e) {} try { Object.getOwnPropertyDescriptor(new Proxy({baz:1}, { getOwnPropertyDescriptor: function() { return { value: 1, configurable: false, writable: true, enumerable: true }; }}), "baz"); return false; } catch(e) {} return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"defineProperty" handler
?
function(){
var proxied = {}; var passed = false; Object.defineProperty( new Proxy(proxied, { defineProperty: function (t, k, d) { passed = t === proxied && k === "foo" && d.value === 5; return true; } }), "foo", { value: 5, configurable: true } ); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"defineProperty" handler invariants
?
function(){
var passed = false; new Proxy({},{}); // A property cannot be added, if the target object is not extensible. var proxied = Object.preventExtensions({}); var proxy = new Proxy(proxied, { defineProperty: function() { passed = true; return true; } }); try { Object.defineProperty(proxy, "foo", { value: 2 }); return false; } catch(e) {} // A property cannot be non-configurable, unless there exists a corresponding // non-configurable own property of the target object. try { Object.defineProperty( new Proxy({ bar: true }, { defineProperty: function () { return true; } }), "bar", { value: 5, configurable: false, writable: true, enumerable: true } ); return false; } catch(e) {} return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"getPrototypeOf" handler
?
function(){
var proxied = {}; var fakeProto = {}; var proxy = new Proxy(proxied, { getPrototypeOf: function (t) { return t === proxied && fakeProto; } }); return Object.getPrototypeOf(proxy) === fakeProto;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"getPrototypeOf" handler invariant
?
function(){
var passed = false; new Proxy({},{}); // If the target object is not extensible, [[GetPrototypeOf]] applied to the proxy object // must return the same value as [[GetPrototypeOf]] applied to the proxy object's target object. try { Object.getPrototypeOf(new Proxy(Object.preventExtensions({}), { getPrototypeOf: function () { passed = true; return {}; } })); return false; } catch(e) {} return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"setPrototypeOf" handler
?
function(){
var proxied = {}; var newProto = {}; var passed = false; Object.setPrototypeOf( new Proxy(proxied, { setPrototypeOf: function (t, p) { passed = t === proxied && p === newProto; return true; } }), newProto ); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"setPrototypeOf" handler invariant
?
function(){
var passed = false; new Proxy({},{}); Object.setPrototypeOf({},{}); // If the target object is not extensible, the argument value must be the // same as the result of [[GetPrototypeOf]] applied to target object. try { Object.setPrototypeOf( new Proxy(Object.preventExtensions({}), { setPrototypeOf: function () { passed = true; return true; } }),{}); return false; } catch(e) {} return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"isExtensible" handler
?
function(){
var proxied = {}; var passed = false; Object.isExtensible( new Proxy(proxied, { isExtensible: function (t) { passed = t === proxied; return true; } }) ); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"isExtensible" handler invariant
?
function(){
var passed = false; new Proxy({},{}); // [[IsExtensible]] applied to the proxy object must return the same value // as [[IsExtensible]] applied to the proxy object's target object with the same argument. try { Object.isExtensible(new Proxy({}, { isExtensible: function (t) { passed = true; return false; } })); return false; } catch(e) {} try { Object.isExtensible(new Proxy(Object.preventExtensions({}), { isExtensible: function (t) { return true; } })); return false; } catch(e) {} return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"preventExtensions" handler
?
function(){
var proxied = {}; var passed = false; Object.preventExtensions( new Proxy(proxied, { preventExtensions: function (t) { passed = t === proxied; return Object.preventExtensions(proxied); } }) ); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"preventExtensions" handler invariant
?
function(){
var passed = false; new Proxy({},{}); // [[PreventExtensions]] applied to the proxy object only returns true // if [[IsExtensible]] applied to the proxy object's target object is false. try { Object.preventExtensions(new Proxy({}, { preventExtensions: function () { passed = true; return true; } })); return false; } catch(e) {} return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"ownKeys" handler
?
function(){
var proxied = {}; var passed = false; Object.keys( new Proxy(proxied, { ownKeys: function (t) { passed = t === proxied; return []; } }) ); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"ownKeys" handler invariant
?
function(){
var passed = false; new Proxy({},{}); // The Type of each result List element is either String or Symbol. try { Object.keys(new Proxy({}, { ownKeys: function () { passed = true; return [2]; }})); return false; } catch(e) {} // The result List must contain the keys of all non-configurable own properties of the target object. var proxied = {}; Object.defineProperty(proxied, "foo", { value: 2, writable: true, enumerable: true }); try { Object.keys(new Proxy(proxied, { ownKeys: function () { return []; }})); return false; } catch(e) {} // If the target object is not extensible, then the result List must contain all the keys // of the own properties of the target object and no other values. try { Object.keys(new Proxy(Object.preventExtensions({b:1}), { ownKeys: function () { return ['a']; }})); return false; } catch(e) {} return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"apply" handler
?
function(){
var proxied = function(){}; var passed = false; var host = { method: new Proxy(proxied, { apply: function (t, thisArg, args) { passed = t === proxied && thisArg === host && args + "" === "foo,bar"; } }) }; host.method("foo", "bar"); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"apply" handler invariant
?
function(){
var passed = false; new Proxy(function(){}, { apply: function () { passed = true; } })(); // A Proxy exotic object only has a [[Call]] internal method if the // initial value of its [[ProxyTarget]] internal slot is an object // that has a [[Call]] internal method. try { new Proxy({}, { apply: function () {} })(); return false; } catch(e) {} return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"construct" handler
?
function(){
var proxied = function(){}; var passed = false; new new Proxy(proxied, { construct: function (t, args) { passed = t === proxied && args + "" === "foo,bar"; return {}; } })("foo","bar"); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§"construct" handler invariants
?
function(){
var passed = false; new Proxy({},{}); // A Proxy exotic object only has a [[Construct]] internal method if the // initial value of its [[ProxyTarget]] internal slot is an object // that has a [[Construct]] internal method. try { new new Proxy({}, { construct: function (t, args) { return {}; } })(); return false; } catch(e) {} // The result of [[Construct]] must be an Object. try { new new Proxy(function(){}, { construct: function (t, args) { passed = true; return 5; } })(); return false; } catch(e) {} return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Proxy.revocable
?
function(){
var obj = Proxy.revocable({}, { get: function() { return 5; } }); var passed = (obj.proxy.foo === 5); obj.revoke(); try { obj.proxy.foo; } catch(e) { passed &= e instanceof TypeError; } return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.isArray support
?
function(){
return Array.isArray(new Proxy([], {}));
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§JSON.stringify support
?
function(){
return JSON.stringify(new Proxy(['foo'], {})) === '["foo"]';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error

Reflect

§Reflect.get
?
function(){
return Reflect.get({ qux: 987 }, "qux") === 987;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.set
?
function(){
var obj = {}; Reflect.set(obj, "quux", 654); return obj.quux === 654;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.has
?
function(){
return Reflect.has({ qux: 987 }, "qux");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.deleteProperty
?
function(){
var obj = { bar: 456 }; Reflect.deleteProperty(obj, "bar"); return !("bar" in obj);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.getOwnPropertyDescriptor
?
function(){
var obj = { baz: 789 }; var desc = Reflect.getOwnPropertyDescriptor(obj, "baz"); return desc.value === 789 && desc.configurable && desc.writable && desc.enumerable;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.defineProperty
?
function(){
var obj = {}; Reflect.defineProperty(obj, "foo", { value: 123 }); return obj.foo === 123 && Reflect.defineProperty(Object.freeze({}), "foo", { value: 123 }) === false;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.getPrototypeOf
?
function(){
return Reflect.getPrototypeOf([]) === Array.prototype;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.setPrototypeOf
?
function(){
var obj = {}; Reflect.setPrototypeOf(obj, Array.prototype); return obj instanceof Array;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.isExtensible
?
function(){
return Reflect.isExtensible({}) && !Reflect.isExtensible(Object.preventExtensions({}));
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.preventExtensions
?
function(){
var obj = {}; Reflect.preventExtensions(obj); return !Object.isExtensible(obj);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.ownKeys, string keys
?
function(){
var obj = Object.create({ C: true }); obj.A = true; Object.defineProperty(obj, 'B', { value: true, enumerable: false }); return Reflect.ownKeys(obj).sort() + '' === "A,B";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.ownKeys, symbol keys
?
function(){
var s1 = Symbol(), s2 = Symbol(), s3 = Symbol(); var proto = {}; proto[s1] = true; var obj = Object.create(proto); obj[s2] = true; Object.defineProperty(obj, s3, { value: true, enumerable: false }); var keys = Reflect.ownKeys(obj); return keys.indexOf(s2) >-1 && keys.indexOf(s3) >-1 && keys.length === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.apply
?
function(){
return Reflect.apply(Array.prototype.push, [1,2], [3,4,5]) === 5;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.construct
?
function(){
return Reflect.construct(function(a, b, c) { this.qux = a + b + c; }, ["foo", "bar", "baz"]).qux === "foobarbaz";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.construct sets new.target meta-property
?
function(){
return Reflect.construct(function(a, b, c) { if (new.target === Object) { this.qux = a + b + c; } }, ["foo", "bar", "baz"], Object).qux === "foobarbaz";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.construct creates instances from third argument
?
function(){
function F(){} var obj = Reflect.construct(function(){ this.y = 1; }, [], F); return obj.y === 1 && obj instanceof F;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.construct, Array subclassing
?
function(){
function F(){} var obj = Reflect.construct(Array, [], F); obj[2] = 'foo'; return obj.length === 3 && obj instanceof F;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.construct, RegExp subclassing
?
function(){
function F(){} var obj = Reflect.construct(RegExp, ["baz","g"], F); return RegExp.prototype.exec.call(obj, "foobarbaz")[0] === "baz" && obj.lastIndex === 9 && obj instanceof F;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.construct, Function subclassing
?
function(){
function F(){} var obj = Reflect.construct(Function, ["return 2"], F); return obj() === 2 && obj instanceof F;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.construct, Promise subclassing
?
function(){
function F(){} var p1 = Reflect.construct(Promise,[function(resolve, reject) { resolve("foo"); }], F); var p2 = Reflect.construct(Promise,[function(resolve, reject) { reject("quux"); }], F); var score = +(p1 instanceof F && p2 instanceof F); function thenFn(result) { score += (result === "foo"); check(); } function catchFn(result) { score += (result === "quux"); check(); } function shouldNotRun(result) { score = -Infinity; } p1.then = p2.then = Promise.prototype.then; p1.catch = p2.catch = Promise.prototype.catch; p1.then(thenFn, shouldNotRun); p2.then(shouldNotRun, catchFn); p1.catch(shouldNotRun); p2.catch(catchFn); function check() { if (score === 4) asyncTestPassed(); }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error

Promise

§basic functionality
?
function(){
var p1 = new Promise(function(resolve, reject) { resolve("foo"); }); var p2 = new Promise(function(resolve, reject) { reject("quux"); }); var score = 0; function thenFn(result) { score += (result === "foo"); check(); } function catchFn(result) { score += (result === "quux"); check(); } function shouldNotRun(result) { score = -Infinity; } p1.then(thenFn, shouldNotRun); p2.then(shouldNotRun, catchFn); p1.catch(shouldNotRun); p2.catch(catchFn); p1.then(function() { // Promise.prototype.then() should return a new Promise score += p1.then() !== p1; check(); }); function check() { if (score === 4) asyncTestPassed(); }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§constructor requires new
?
function(){
new Promise(function(){}); try { Promise(function(){}); return false; } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§Promise.prototype isn't an instance
?
function(){
new Promise(function(){}); try { Promise.prototype.then(function(){}); } catch (e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§Promise.all
?
function(){
var fulfills = Promise.all([ new Promise(function(resolve) { setTimeout(resolve,2000,"foo"); }), new Promise(function(resolve) { setTimeout(resolve,1000,"bar"); }), ]); var rejects = Promise.all([ new Promise(function(_, reject) { setTimeout(reject, 2000,"baz"); }), new Promise(function(_, reject) { setTimeout(reject, 1000,"qux"); }), ]); var score = 0; fulfills.then(function(result) { score += (result + "" === "foo,bar"); check(); }); rejects.catch(function(result) { score += (result === "qux"); check(); }); function check() { if (score === 2) asyncTestPassed(); }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§Promise.all, generic iterables
?
function(){
var fulfills = Promise.all(global.__createIterableObject([ new Promise(function(resolve) { setTimeout(resolve,2000,"foo"); }), new Promise(function(resolve) { setTimeout(resolve,1000,"bar"); }), ])); var rejects = Promise.all(global.__createIterableObject([ new Promise(function(_, reject) { setTimeout(reject, 2000,"baz"); }), new Promise(function(_, reject) { setTimeout(reject, 1000,"qux"); }), ])); var score = 0; fulfills.then(function(result) { score += (result + "" === "foo,bar"); check(); }); rejects.catch(function(result) { score += (result === "qux"); check(); }); function check() { if (score === 2) asyncTestPassed(); }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error
§Promise.race
?
function(){
var fulfills = Promise.race([ new Promise(function(resolve) { setTimeout(resolve,1000,"foo"); }), new Promise(function(_, reject) { setTimeout(reject, 2000,"bar"); }), ]); var rejects = Promise.race([ new Promise(function(_, reject) { setTimeout(reject, 1000,"baz"); }), new Promise(function(resolve) { setTimeout(resolve,2000,"qux"); }), ]); var score = 0; fulfills.then(function(result) { score += (result === "foo"); check(); }); rejects.catch(function(result) { score += (result === "baz"); check(); }); function check() { if (score === 2) asyncTestPassed(); }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§Promise.race, generic iterables
?
function(){
var fulfills = Promise.race(global.__createIterableObject([ new Promise(function(resolve) { setTimeout(resolve,1000,"foo"); }), new Promise(function(_, reject) { setTimeout(reject, 2000,"bar"); }), ])); var rejects = Promise.race(global.__createIterableObject([ new Promise(function(_, reject) { setTimeout(reject, 1000,"baz"); }), new Promise(function(resolve) { setTimeout(resolve,2000,"qux"); }), ])); var score = 0; fulfills.then(function(result) { score += (result === "foo"); check(); }); rejects.catch(function(result) { score += (result === "baz"); check(); }); function check() { if (score === 2) asyncTestPassed(); }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error
§Promise[Symbol.species]
?
function(){
var prop = Object.getOwnPropertyDescriptor(Promise, Symbol.species); return 'get' in prop && Promise[Symbol.species] === Promise;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error

Symbol

§basic functionality
?
function(){
var object = {}; var symbol = Symbol(); var value = {}; object[symbol] = value; return object[symbol] === value;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§typeof support
?
function(){
return typeof Symbol() === "symbol";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§symbol keys are hidden to pre-ES6 code
?
function(){
var object = {}; var symbol = Symbol(); object[symbol] = 1; for (var x in object){} var passed = !x; if (Object.keys && Object.getOwnPropertyNames) { passed &= Object.keys(object).length === 0 && Object.getOwnPropertyNames(object).length === 0; } return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§Object.defineProperty support
?
function(){
var object = {}; var symbol = Symbol(); var value = {}; if (Object.defineProperty) { Object.defineProperty(object, symbol, { value: value }); return object[symbol] === value; } return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§symbols inherit from Symbol.prototype
?
function(){
var symbol = Symbol(); var passed = symbol.foo === undefined; Symbol.prototype.foo = 2; passed &= symbol.foo === 2; delete Symbol.prototype.foo; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§cannot coerce to string or number
?
function(){
var symbol = Symbol(); try { symbol + ""; return false; } catch(e) {} try { symbol + 0; return false; } catch(e) {} return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§can convert with String()
?
function(){
return String(Symbol("foo")) === "Symbol(foo)";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§new Symbol() throws
?
function(){
var symbol = Symbol(); try { new Symbol(); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§Object(symbol)
?
function(){
var symbol = Symbol(); var symbolObject = Object(symbol); return typeof symbolObject === "object" && symbolObject instanceof Symbol && symbolObject == symbol && symbolObject !== symbol && symbolObject.valueOf() === symbol;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
§JSON.stringify ignores symbol primitives
?
function(){
var object = { foo: Symbol() }; object[Symbol()] = 1; var array = [Symbol()]; return JSON.stringify(object) === '{}' && JSON.stringify(array) === '[null]' && JSON.stringify(Symbol()) === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§JSON.stringify ignores symbol objects
?
function(){
var testSymbolObject = function (sym) { var object = { foo: sym }; try { // some browsers throw a TypeError when setting symbol object keys. // this isn't part of this test, so, ignore it if so. object[sym] = 1; } catch (e) {} // some browsers throw a TypeError when setting symbol object keys. var array = [sym]; return JSON.stringify(object) === '{"foo":{}}' && JSON.stringify(array) === '[{}]' && JSON.stringify(sym) === '{}'; }; var objSym = Object(Symbol()); var symNoToJSON = Object(Symbol()); Object.defineProperty(symNoToJSON, 'toJSON', { enumerable: false, value: null }); // ensure it overrides the prototype, but is not callable return testSymbolObject(objSym) && testSymbolObject(symNoToJSON);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
§global symbol registry
?
function(){
var symbol = Symbol.for('foo'); return Symbol.for('foo') === symbol && Symbol.keyFor(symbol) === 'foo';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error

well-known symbols

§Symbol.hasInstance
?
function(){
var passed = false; var obj = { foo: true }; var C = function(){}; Object.defineProperty(C, Symbol.hasInstance, { value: function(inst) { passed = inst.foo; return false; } }); obj instanceof C; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
Error
Error
§Symbol.isConcatSpreadable
?
function(){
var a = [], b = []; b[Symbol.isConcatSpreadable] = false; a = a.concat(b); return a[0] === b;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
§Symbol.iterator, existence
?
function(){
return "iterator" in Symbol;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§Symbol.iterator, arguments object
?
function(){
return (function() { return typeof arguments[Symbol.iterator] === 'function' && Object.hasOwnProperty.call(arguments, Symbol.iterator); }());
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error
§Symbol.species, existence
?
function(){
return "species" in Symbol;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
Error
Error
§Symbol.species, Array.prototype.concat
?
function(){
var obj = []; obj.constructor = {}; obj.constructor[Symbol.species] = function() { return { foo: 1 }; }; return Array.prototype.concat.call(obj, []).foo === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
Error
Error
§Symbol.species, Array.prototype.filter
?
function(){
var obj = []; obj.constructor = {}; obj.constructor[Symbol.species] = function() { return { foo: 1 }; }; return Array.prototype.filter.call(obj, Boolean).foo === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
Error
Error
§Symbol.species, Array.prototype.map
?
function(){
var obj = []; obj.constructor = {}; obj.constructor[Symbol.species] = function() { return { foo: 1 }; }; return Array.prototype.map.call(obj, Boolean).foo === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
Error
Error
§Symbol.species, Array.prototype.slice
?
function(){
var obj = []; obj.constructor = {}; obj.constructor[Symbol.species] = function() { return { foo: 1 }; }; return Array.prototype.slice.call(obj, 0).foo === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
Error
Error
§Symbol.species, Array.prototype.splice
?
function(){
var obj = []; obj.constructor = {}; obj.constructor[Symbol.species] = function() { return { foo: 1 }; }; return Array.prototype.splice.call(obj, 0).foo === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
Error
Error
§Symbol.species, RegExp.prototype[Symbol.split]
?
function(){
var passed = false; var obj = { constructor: {} }; obj[Symbol.split] = RegExp.prototype[Symbol.split]; obj.constructor[Symbol.species] = function() { passed = true; return /./; }; "".split(obj); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
No
No
No
No
No
No
Error
Error
§Symbol.species, Promise.prototype.then
?
function(){
var promise = new Promise(function(resolve){ resolve(42); }); var FakePromise1 = promise.constructor = function(exec){ exec(function(){}, function(){}); }; var FakePromise2 = function(exec){ exec(function(){}, function(){}); }; Object.defineProperty(FakePromise1, Symbol.species, {value: FakePromise2}); return promise.then(function(){}) instanceof FakePromise2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
Error
Error
§Symbol.replace
?
function(){
var O = {}; O[Symbol.replace] = function(){ return 42; }; return ''.replace(O) === 42;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
§Symbol.search
?
function(){
var O = {}; O[Symbol.search] = function(){ return 42; }; return ''.search(O) === 42;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
§Symbol.split
?
function(){
var O = {}; O[Symbol.split] = function(){ return 42; }; return ''.split(O) === 42;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
§Symbol.match
?
function(){
var O = {}; O[Symbol.match] = function(){ return 42; }; return ''.match(O) === 42;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
§Symbol.match, RegExp constructor
?
function(){
var re = /./; re[Symbol.match] = false; var foo = {constructor: RegExp}; foo[Symbol.match] = true; return RegExp(re) !== re && RegExp(foo) === foo;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
§Symbol.match, String.prototype.startsWith
?
function(){
var re = /./; try { '/./'.startsWith(re); } catch(e){ re[Symbol.match] = false; return '/./'.startsWith(re); }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§Symbol.match, String.prototype.endsWith
?
function(){
var re = /./; try { '/./'.endsWith(re); } catch(e){ re[Symbol.match] = false; return '/./'.endsWith(re); }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§Symbol.match, String.prototype.includes
?
function(){
var re = /./; try { '/./'.includes(re); } catch(e){ re[Symbol.match] = false; return '/./'.includes(re); }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§Symbol.toPrimitive
?
function(){
var a = {}, b = {}, c = {}; var passed = 0; a[Symbol.toPrimitive] = function(hint) { passed += hint === "number"; return 0; }; b[Symbol.toPrimitive] = function(hint) { passed += hint === "string"; return 0; }; c[Symbol.toPrimitive] = function(hint) { passed += hint === "default"; return 0; }; a >= 0; b in {}; c == 0; return passed === 3;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
§Symbol.toStringTag
?
function(){
var a = {}; a[Symbol.toStringTag] = "foo"; return (a + "") === "[object foo]";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
Flag
No
No
Error
Error
§Symbol.toStringTag affects existing built-ins
?
function(){
var s = Symbol.toStringTag; var passed = true; [ [Array.prototype, []], [String.prototype, ''], [arguments, arguments], [Function.prototype, function(){}], [Error.prototype, new Error()], [Boolean.prototype, true], [Number.prototype, 2], [Date.prototype, new Date()], [RegExp.prototype, /./] ].forEach(function(pair){ pair[0][s] = "foo"; passed &= (Object.prototype.toString.call(pair[1]) === "[object foo]"); delete pair[0][s]; }); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Yes
Yes
Yes
Yes
No
Flag
No
Flag
No
No
Error
Error
§Symbol.toStringTag, new built-ins
?
function(){
var passed = true; var s = Symbol.toStringTag; [ [String, "String Iterator"], [Array, "Array Iterator"], [Map, "Map Iterator"], [Set, "Set Iterator"] ].forEach(function(pair){ var iterProto = Object.getPrototypeOf(new pair[0]()[Symbol.iterator]()); passed = passed && iterProto.hasOwnProperty(s) && iterProto[s] === pair[1]; }); passed = passed && Object.getPrototypeOf(function*(){})[s] === "GeneratorFunction" && Object.getPrototypeOf(function*(){}())[s] === "Generator" && Map.prototype[s] === "Map" && Set.prototype[s] === "Set" && ArrayBuffer.prototype[s] === "ArrayBuffer" && DataView.prototype[s] === "DataView" && Promise.prototype[s] === "Promise" && Symbol.prototype[s] === "Symbol" && typeof Object.getOwnPropertyDescriptor( Object.getPrototypeOf(Int8Array).prototype, Symbol.toStringTag).get === "function"; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Error
No
Error
Error
No
Error
Error
§Symbol.toStringTag, misc. built-ins
?
function(){
var s = Symbol.toStringTag; return Math[s] === "Math" && JSON[s] === "JSON";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
Flag
No
No
Error
Error
§Symbol.unscopables
?
function(){
var a = { foo: 1, bar: 2 }; a[Symbol.unscopables] = { bar: true }; with (a) { return foo === 1 && typeof bar === "undefined"; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error

built-in extensions

Object static methods

§Object.assign
?
function(){
var o = Object.assign({a:true}, {b:true}, {c:true}); return "a" in o && "b" in o && "c" in o;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§Object.is
?
function(){
return typeof Object.is === 'function' && Object.is(NaN, NaN) && !Object.is(-0, 0);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§Object.getOwnPropertySymbols
?
function(){
var o = {}; var sym = Symbol(), sym2 = Symbol(), sym3 = Symbol(); o[sym] = true; o[sym2] = true; o[sym3] = true; var result = Object.getOwnPropertySymbols(o); return result[0] === sym && result[1] === sym2 && result[2] === sym3;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§Object.setPrototypeOf
?
function(){
return Object.setPrototypeOf({}, Array.prototype) instanceof Array;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error

function "name" property

§function statements
?
function(){
function foo(){}; return foo.name === 'foo' && (function(){}).name === '';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§function expressions
?
function(){
return (function foo(){}).name === 'foo' && (function(){}).name === '';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§new Function
?
function(){
return (new Function).name === "anonymous";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
§bound functions
?
function(){
function foo() {}; return foo.bind({}).name === "bound foo" && (function(){}).bind({}).name === "bound ";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§variables (function)
?
function(){
var foo = function() {}; var bar = function baz() {}; return foo.name === "foo" && bar.name === "baz";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
No
No
§object methods (function)
?
function(){
var o = { foo: function(){}, bar: function baz(){}}; o.qux = function(){}; return o.foo.name === "foo" && o.bar.name === "baz" && o.qux.name === "";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
No
No
§accessor properties
?
function(){
var o = { get foo(){}, set foo(x){} }; var descriptor = Object.getOwnPropertyDescriptor(o, "foo"); return descriptor.get.name === "get foo" && descriptor.set.name === "set foo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
No
No
§shorthand methods
?
function(){
var o = { foo(){} }; return o.foo.name === "foo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§shorthand methods (no lexical binding)
?
function(){
var f = "foo"; return ({f() { return f; }}).f() === "foo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§symbol-keyed methods
?
function(){
var sym1 = Symbol("foo"); var sym2 = Symbol(); var o = { [sym1]: function(){}, [sym2]: function(){} }; return o[sym1].name === "[foo]" && o[sym2].name === "";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
Error
Error
Error
Error
§class statements
?
function(){
class foo {}; class bar { static name() {} }; return foo.name === "foo" && typeof bar.name === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§class expressions
?
function(){
return class foo {}.name === "foo" && typeof class bar { static name() {} }.name === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§variables (class)
?
function(){
var foo = class {}; var bar = class baz {}; var qux = class { static name() {} }; return foo.name === "foo" && bar.name === "baz" && typeof qux.name === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
Error
No
Error
Error
Error
Error
Error
Error
§object methods (class)
?
function(){
var o = { foo: class {}, bar: class baz {}}; o.qux = class {}; return o.foo.name === "foo" && o.bar.name === "baz" && o.qux.name === "";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
Error
No
Error
Error
Error
Error
Error
Error
§class prototype methods
?
function(){
class C { foo(){} }; return (new C).foo.name === "foo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§class static methods
?
function(){
class C { static foo(){} }; return C.foo.name === "foo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§isn't writable, is configurable
?
function(){
var descriptor = Object.getOwnPropertyDescriptor(function f(){},"name"); return descriptor.enumerable === false && descriptor.writable === false && descriptor.configurable === true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No

String static methods

§String.raw
?
function(){
return typeof String.raw === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§String.fromCodePoint
?
function(){
return typeof String.fromCodePoint === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No

String.prototype methods

§String.prototype.codePointAt
?
function(){
return typeof String.prototype.codePointAt === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
§String.prototype.normalize
?
function(){
return typeof String.prototype.normalize === "function" && "c\u0327\u0301".normalize("NFC") === "\u1e09" && "\u1e09".normalize("NFD") === "c\u0327\u0301";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§String.prototype.repeat
?
function(){
return typeof String.prototype.repeat === 'function' && "foo".repeat(3) === "foofoofoo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
§String.prototype.startsWith
?
function(){
return typeof String.prototype.startsWith === 'function' && "foobar".startsWith("foo");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
§String.prototype.startsWith throws on RegExp
?
function(){
try { "a".startsWith(/./); } catch(e) { return typeof String.prototype.startsWith === 'function'; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
§String.prototype.endsWith
?
function(){
return typeof String.prototype.endsWith === 'function' && "foobar".endsWith("bar");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
§String.prototype.endsWith throws on RegExp
?
function(){
try { "a".endsWith(/./); } catch(e) { return typeof String.prototype.endsWith === 'function'; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
§String.prototype.includes
?
function(){
return typeof String.prototype.includes === 'function' && "foobar".includes("oba");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§String.prototype[Symbol.iterator]
?
function(){
return typeof String.prototype[Symbol.iterator] === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§String iterator prototype chain
?
function(){
// Iterator instance var iterator = ''[Symbol.iterator](); // %StringIteratorPrototype% var proto1 = Object.getPrototypeOf(iterator); // %IteratorPrototype% var proto2 = Object.getPrototypeOf(proto1); return proto2.hasOwnProperty(Symbol.iterator) && !proto1 .hasOwnProperty(Symbol.iterator) && !iterator .hasOwnProperty(Symbol.iterator) && iterator[Symbol.iterator]() === iterator;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error

RegExp.prototype properties

§RegExp.prototype.flags
?
function(){
return /./igm.flags === "gim" && /./.flags === "";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
§RegExp.prototype[Symbol.match]
?
function(){
return typeof RegExp.prototype[Symbol.match] === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
§RegExp.prototype[Symbol.replace]
?
function(){
return typeof RegExp.prototype[Symbol.replace] === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
§RegExp.prototype[Symbol.split]
?
function(){
return typeof RegExp.prototype[Symbol.split] === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
§RegExp.prototype[Symbol.search]
?
function(){
return typeof RegExp.prototype[Symbol.search] === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
§RegExp[Symbol.species]
?
function(){
var prop = Object.getOwnPropertyDescriptor(RegExp, Symbol.species); return 'get' in prop && RegExp[Symbol.species] === RegExp;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error

Array static methods

§Array.from, array-like objects
?
function(){
return Array.from({ 0: "foo", 1: "bar", length: 2 }) + '' === "foo,bar";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§Array.from, generator instances
?
function(){
var iterable = (function*(){ yield 1; yield 2; yield 3; }()); return Array.from(iterable) + '' === "1,2,3";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§Array.from, generic iterables
?
function(){
var iterable = global.__createIterableObject([1, 2, 3]); return Array.from(iterable) + '' === "1,2,3";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§Array.from, instances of generic iterables
?
function(){
var iterable = global.__createIterableObject([1, 2, 3]); return Array.from(Object.create(iterable)) + '' === "1,2,3";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§Array.from map function, array-like objects
?
function(){
return Array.from({ 0: "foo", 1: "bar", length: 2 }, function(e, i) { return e + this.baz + i; }, { baz: "d" }) + '' === "food0,bard1";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§Array.from map function, generator instances
?
function(){
var iterable = (function*(){ yield "foo"; yield "bar"; yield "bal"; }()); return Array.from(iterable, function(e, i) { return e + this.baz + i; }, { baz: "d" }) + '' === "food0,bard1,bald2";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§Array.from map function, generic iterables
?
function(){
var iterable = global.__createIterableObject(["foo", "bar", "bal"]); return Array.from(iterable, function(e, i) { return e + this.baz + i; }, { baz: "d" }) + '' === "food0,bard1,bald2";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§Array.from map function, instances of iterables
?
function(){
var iterable = global.__createIterableObject(["foo", "bar", "bal"]); return Array.from(Object.create(iterable), function(e, i) { return e + this.baz + i; }, { baz: "d" }) + '' === "food0,bard1,bald2";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§Array.from, iterator closing
?
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); try { Array.from(iter, function() { throw 42 }); } catch(e){} return closed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
§Array.of
?
function(){
return typeof Array.of === 'function' && Array.of(2)[0] === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§Array[Symbol.species]
?
function(){
var prop = Object.getOwnPropertyDescriptor(Array, Symbol.species); return 'get' in prop && Array[Symbol.species] === Array;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error

Array.prototype methods

§Array.prototype.copyWithin
?
function(){
return typeof Array.prototype.copyWithin === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§Array.prototype.find
?
function(){
return typeof Array.prototype.find === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
§Array.prototype.findIndex
?
function(){
return typeof Array.prototype.findIndex === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
§Array.prototype.fill
?
function(){
return typeof Array.prototype.fill === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
§Array.prototype.keys
?
function(){
return typeof Array.prototype.keys === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Array.prototype.values
?
function(){
return typeof Array.prototype.values === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Yes
Yes
No
No
§Array.prototype.entries
?
function(){
return typeof Array.prototype.entries === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Array.prototype[Symbol.iterator]
?
function(){
return typeof Array.prototype[Symbol.iterator] === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§Array iterator prototype chain
?
function(){
// Iterator instance var iterator = [][Symbol.iterator](); // %ArrayIteratorPrototype% var proto1 = Object.getPrototypeOf(iterator); // %IteratorPrototype% var proto2 = Object.getPrototypeOf(proto1); return proto2.hasOwnProperty(Symbol.iterator) && !proto1 .hasOwnProperty(Symbol.iterator) && !iterator .hasOwnProperty(Symbol.iterator) && iterator[Symbol.iterator]() === iterator;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
Error
Error
§Array.prototype[Symbol.unscopables]
?
function(){
var unscopables = Array.prototype[Symbol.unscopables]; if (!unscopables) { return false; } var ns = "find,findIndex,fill,copyWithin,entries,keys,values".split(","); for (var i = 0; i < ns.length; i++) { if (Array.prototype[ns[i]] && !unscopables[ns[i]]) return false; } return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error

Number properties

§Number.isFinite
?
function(){
return typeof Number.isFinite === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§Number.isInteger
?
function(){
return typeof Number.isInteger === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Number.isSafeInteger
?
function(){
return typeof Number.isSafeInteger === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Number.isNaN
?
function(){
return typeof Number.isNaN === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§Number.parseFloat
?
function(){
var actualGlobal = Function('return this')(); return typeof Number.parseFloat === 'function' && Number.parseFloat === actualGlobal.parseFloat;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Number.parseInt
?
function(){
var actualGlobal = Function('return this')(); return typeof Number.parseInt === 'function' && Number.parseInt === actualGlobal.parseInt;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Number.EPSILON
?
function(){
return typeof Number.EPSILON === 'number';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Number.MIN_SAFE_INTEGER
?
function(){
return typeof Number.MIN_SAFE_INTEGER === 'number';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Number.MAX_SAFE_INTEGER
?
function(){
return typeof Number.MAX_SAFE_INTEGER === 'number';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No

Math methods

§Math.clz32
?
function(){
return typeof Math.clz32 === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Math.imul
?
function(){
return typeof Math.imul === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Math.sign
?
function(){
return typeof Math.sign === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Math.log10
?
function(){
return typeof Math.log10 === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Math.log2
?
function(){
return typeof Math.log2 === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Math.log1p
?
function(){
return typeof Math.log1p === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Math.expm1
?
function(){
return typeof Math.expm1 === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Math.cosh
?
function(){
return typeof Math.cosh === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Math.sinh
?
function(){
return typeof Math.sinh === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Math.tanh
?
function(){
return typeof Math.tanh === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Math.acosh
?
function(){
return typeof Math.acosh === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Math.asinh
?
function(){
return typeof Math.asinh === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Math.atanh
?
function(){
return typeof Math.atanh === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Math.trunc
?
function(){
return typeof Math.trunc === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Math.fround
?
function(){
return typeof Math.fround === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Math.cbrt
?
function(){
return typeof Math.cbrt === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§Math.hypot
?
function(){
return Math.hypot() === 0 && Math.hypot(1) === 1 && Math.hypot(9, 12, 20) === 25 && Math.hypot(27, 36, 60, 100) === 125;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error

§Date.prototype[Symbol.toPrimitive]
?
function(){
var tp = Date.prototype[Symbol.toPrimitive]; return tp.call(Object(2), "number") === 2 && tp.call(Object(2), "string") === "2" && tp.call(Object(2), "default") === "2";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error

subclassing

Array is subclassable

§length property (accessing)
?
function(){
class C extends Array {} var c = new C(); var len1 = c.length; c[2] = 'foo'; var len2 = c.length; return len1 === 0 && len2 === 3;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§length property (setting)
?
function(){
class C extends Array {} var c = new C(); c[2] = 'foo'; c.length = 1; return c.length === 1 && !(2 in c);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§correct prototype chain
?
function(){
class C extends Array {} var c = new C(); return c instanceof C && c instanceof Array && Object.getPrototypeOf(C) === Array;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§Array.isArray support
?
function(){
class C extends Array {} return Array.isArray(new C());
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§Array.prototype.concat
?
function(){
class C extends Array {} var c = new C(); return c.concat(1) instanceof C;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
Error
No
Error
Error
Error
Error
Error
Error
§Array.prototype.filter
?
function(){
class C extends Array {} var c = new C(); return c.filter(Boolean) instanceof C;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
Error
No
Error
Error
Error
Error
Error
Error
§Array.prototype.map
?
function(){
class C extends Array {} var c = new C(); return c.map(Boolean) instanceof C;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
Error
No
Error
Error
Error
Error
Error
Error
§Array.prototype.slice
?
function(){
class C extends Array {} var c = new C(); c.push(2,4,6); return c.slice(1,2) instanceof C;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
Error
No
Error
Error
Error
Error
Error
Error
§Array.prototype.splice
?
function(){
class C extends Array {} var c = new C(); c.push(2,4,6); return c.splice(1,2) instanceof C;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
Error
No
Error
Error
Error
Error
Error
Error
§Array.from
?
function(){
class C extends Array {} return C.from({ length: 0 }) instanceof C;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§Array.of
?
function(){
class C extends Array {} return C.of(0) instanceof C;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error

RegExp is subclassable

§basic functionality
?
function(){
class R extends RegExp {} var r = new R("baz","g"); return r.global && r.source === "baz";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§correct prototype chain
?
function(){
class R extends RegExp {} var r = new R("baz","g"); return r instanceof R && r instanceof RegExp && Object.getPrototypeOf(R) === RegExp;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§RegExp.prototype.exec
?
function(){
class R extends RegExp {} var r = new R("baz","g"); return r.exec("foobarbaz")[0] === "baz" && r.lastIndex === 9;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§RegExp.prototype.test
?
function(){
class R extends RegExp {} var r = new R("baz"); return r.test("foobarbaz");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error

Function is subclassable

§can be called
?
function(){
class C extends Function {} var c = new C("return 'foo';"); return c() === 'foo';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§correct prototype chain
?
function(){
class C extends Function {} var c = new C("return 'foo';"); return c instanceof C && c instanceof Function && Object.getPrototypeOf(C) === Function;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
Error
Error
Error
Error
Error
Error
§can be used with "new"
?
function(){
class C extends Function {} var c = new C("this.bar = 2;"); c.prototype.baz = 3; return new c().bar === 2 && new c().baz === 3;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§Function.prototype.call
?
function(){
class C extends Function {} var c = new C("x", "return this.bar + x;"); return c.call({bar:1}, 2) === 3;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§Function.prototype.apply
?
function(){
class C extends Function {} var c = new C("x", "return this.bar + x;"); return c.apply({bar:1}, [2]) === 3;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§Function.prototype.bind
?
function(){
class C extends Function {} var c = new C("x", "y", "return this.bar + x + y;").bind({bar:1}, 2); return c(6) === 9 && c instanceof C;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
Error
Error
Error
Error
Error
Error

Promise is subclassable

§basic functionality
?
function(){
class P extends Promise {} var p1 = new P(function(resolve, reject) { resolve("foo"); }); var p2 = new P(function(resolve, reject) { reject("quux"); }); var score = +(p1 instanceof P); function thenFn(result) { score += (result === "foo"); check(); } function catchFn(result) { score += (result === "quux"); check(); } function shouldNotRun(result) { score = -Infinity; } p1.then(thenFn, shouldNotRun); p2.then(shouldNotRun, catchFn); p1.catch(shouldNotRun); p2.catch(catchFn); p1.then(function() { // P.prototype.then() should return a new P score += p1.then() instanceof P && p1.then() !== p1; check(); }); function check() { if (score === 5) asyncTestPassed(); }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§correct prototype chain
?
function(){
class C extends Promise {} var c = new C(function(resolve, reject) { resolve("foo"); }); return c instanceof C && c instanceof Promise && Object.getPrototypeOf(C) === Promise;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§Promise.all
?
function(){
class P extends Promise {} var fulfills = P.all([ new Promise(function(resolve) { setTimeout(resolve,2000,"foo"); }), new Promise(function(resolve) { setTimeout(resolve,1000,"bar"); }), ]); var rejects = P.all([ new Promise(function(_, reject) { setTimeout(reject, 2000,"baz"); }), new Promise(function(_, reject) { setTimeout(reject, 1000,"qux"); }), ]); var score = +(fulfills instanceof P); fulfills.then(function(result) { score += (result + "" === "foo,bar"); check(); }); rejects.catch(function(result) { score += (result === "qux"); check(); }); function check() { if (score === 3) asyncTestPassed(); }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§Promise.race
?
function(){
class P extends Promise {} var fulfills = P.race([ new Promise(function(resolve) { setTimeout(resolve,1000,"foo"); }), new Promise(function(_, reject) { setTimeout(reject, 2000,"bar"); }), ]); var rejects = P.race([ new Promise(function(_, reject) { setTimeout(reject, 1000,"baz"); }), new Promise(function(resolve) { setTimeout(resolve,2000,"qux"); }), ]); var score = +(fulfills instanceof P); fulfills.then(function(result) { score += (result === "foo"); check(); }); rejects.catch(function(result) { score += (result === "baz"); check(); }); function check() { if (score === 3) asyncTestPassed(); }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error

miscellaneous subclassables

§Boolean is subclassable
?
function(){
class C extends Boolean {} var c = new C(true); return c instanceof Boolean && c instanceof C && c == true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§Number is subclassable
?
function(){
class C extends Number {} var c = new C(6); return c instanceof Number && c instanceof C && +c === 6;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§String is subclassable
?
function(){
class C extends String {} var c = new C("golly"); return c instanceof String && c instanceof C && c + '' === "golly" && c[0] === "g" && c.length === 5;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
Error
Error
Error
Error
Error
Error
§Error is subclassable
?
function(){
class C extends Error {} var c = new C(); return c instanceof Error && c instanceof C && Object.prototype.toString.call(c) === "[object Error]";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§Map is subclassable
?
function(){
var key = {}; class M extends Map {} var map = new M(); map.set(key, 123); return map instanceof M && map.has(key) && map.get(key) === 123;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§Set is subclassable
?
function(){
var obj = {}; class S extends Set {} var set = new S(); set.add(123); set.add(123); return set instanceof S && set.has(123);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error

misc

prototype of bound functions

§basic functions
?
function(){
function correctProtoBound(proto) { var f = function(){}; if (Object.setPrototypeOf) { Object.setPrototypeOf(f, proto); } else { f.__proto__ = proto; } var boundF = Function.prototype.bind.call(f, null); return Object.getPrototypeOf(boundF) === proto; } return correctProtoBound(Function.prototype) && correctProtoBound({}) && correctProtoBound(null);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
§generator functions
?
function(){
function correctProtoBound(proto) { var f = function*(){}; if (Object.setPrototypeOf) { Object.setPrototypeOf(f, proto); } else { f.__proto__ = proto; } var boundF = Function.prototype.bind.call(f, null); return Object.getPrototypeOf(boundF) === proto; } return correctProtoBound(Function.prototype) && correctProtoBound({}) && correctProtoBound(null);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
No
Error
Error
§arrow functions
?
function(){
function correctProtoBound(proto) { var f = ()=>5; if (Object.setPrototypeOf) { Object.setPrototypeOf(f, proto); } else { f.__proto__ = proto; } var boundF = Function.prototype.bind.call(f, null); return Object.getPrototypeOf(boundF) === proto; } return correctProtoBound(Function.prototype) && correctProtoBound({}) && correctProtoBound(null);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
No
Error
Error
§classes
?
function(){
function correctProtoBound(proto) { class C {} if (Object.setPrototypeOf) { Object.setPrototypeOf(C, proto); } else { C.__proto__ = proto; } var boundF = Function.prototype.bind.call(C, null); return Object.getPrototypeOf(boundF) === proto; } return correctProtoBound(Function.prototype) && correctProtoBound({}) && correctProtoBound(null);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
§subclasses
?
function(){
function correctProtoBound(superclass) { class C extends superclass { constructor() { return Object.create(null); } } var boundF = Function.prototype.bind.call(C, null); return Object.getPrototypeOf(boundF) === Object.getPrototypeOf(C); } return correctProtoBound(function(){}) && correctProtoBound(Array) && correctProtoBound(null);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error

Proxy, internal 'get' calls

§ToPrimitive
?
function(){
// ToPrimitive -> Get -> [[Get]] var get = []; var p = new Proxy({toString:Function()}, { get: function(o, k) { get.push(k); return o[k]; }}); p + 3; return get[0] === Symbol.toPrimitive && get.slice(1) + '' === "valueOf,toString";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§CreateListFromArrayLike
?
function(){
// CreateListFromArrayLike -> Get -> [[Get]] var get = []; var p = new Proxy({length:2, 0:0, 1:0}, { get: function(o, k) { get.push(k); return o[k]; }}); Function.prototype.apply({}, p); return get + '' === "length,0,1";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§instanceof operator
?
function(){
// InstanceofOperator -> GetMethod -> GetV -> [[Get]] // InstanceofOperator -> OrdinaryHasInstance -> Get -> [[Get]] var get = []; var p = new Proxy(Function(), { get: function(o, k) { get.push(k); return o[k]; }}); ({}) instanceof p; return get[0] === Symbol.hasInstance && get.slice(1) + '' === "prototype";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
Error
Error
Error
Error
Error
Error
Error
Error
§HasBinding
?
function(){
// HasBinding -> Get -> [[Get]] var get = []; var p = new Proxy({foo:1}, { get: function(o, k) { get.push(k); return o[k]; }}); p[Symbol.unscopables] = p; with(p) { typeof foo; } return get[0] === Symbol.unscopables && get.slice(1) + '' === "foo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§CreateDynamicFunction
?
function(){
// CreateDynamicFunction -> GetPrototypeFromConstructor -> Get -> [[Get]] var get = []; var p = new Proxy(Function, { get: function(o, k) { get.push(k); return o[k]; }}); new p; return get + '' === "prototype";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§ClassDefinitionEvaluation
?
function(){
// ClassDefinitionEvaluation -> Get -> [[Get]] var get = []; var p = new Proxy(Function(), { get: function(o, k) { get.push(k); return o[k]; }}); class C extends p {} return get + '' === "prototype";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§IteratorComplete, IteratorValue
?
function(){
// IteratorComplete -> Get -> [[Get]] // IteratorValue -> Get -> [[Get]] var get = []; var iterable = {}; iterable[Symbol.iterator] = function() { return { next: function() { return new Proxy({ value: 2, done: false }, { get: function(o, k) { get.push(k); return o[k]; }}); } }; } var i = 0; for(var e of iterable) { if (++i >= 2) break; } return get + '' === "done,value,done,value";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§ToPropertyDescriptor
?
function(){
// ToPropertyDescriptor -> Get -> [[Get]] var get = []; var p = new Proxy({ enumerable: true, configurable: true, value: true, writable: true, get: Function(), set: Function() }, { get: function(o, k) { get.push(k); return o[k]; }}); try { // This will throw, since it will have true for both "get" and "value", // but not before performing a Get on every property. Object.defineProperty({}, "foo", p); } catch(e) { return get + '' === "enumerable,configurable,value,writable,get,set"; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Object.assign
?
function(){
// Object.assign -> Get -> [[Get]] var get = []; var p = new Proxy({foo:1, bar:2}, { get: function(o, k) { get.push(k); return o[k]; }}); Object.assign({}, p); return get + '' === "foo,bar";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Object.defineProperties
?
function(){
// Object.defineProperties -> Get -> [[Get]] var get = []; var p = new Proxy({foo:{}, bar:{}}, { get: function(o, k) { get.push(k); return o[k]; }}); Object.defineProperties({}, p); return get + '' === "foo,bar";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Function.prototype.bind
?
function(){
// Function.prototype.bind -> Get -> [[Get]] var get = []; var p = new Proxy(Function(), { get: function(o, k) { get.push(k); return o[k]; }}); Function.prototype.bind.call(p); return get + '' === "length,name";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Error.prototype.toString
?
function(){
// Error.prototype.toString -> Get -> [[Get]] var get = []; var p = new Proxy({}, { get: function(o, k) { get.push(k); return o[k]; }}); Error.prototype.toString.call(p); return get + '' === "name,message";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§String.raw
?
function(){
// String.raw -> Get -> [[Get]] var get = []; var raw = new Proxy({length: 2, 0: '', 1: ''}, { get: function(o, k) { get.push(k); return o[k]; }}); var p = new Proxy({raw: raw}, { get: function(o, k) { get.push(k); return o[k]; }}); String.raw(p); return get + '' === "raw,length,0,1";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§RegExp constructor
?
function(){
// RegExp -> Get -> [[Get]] var get = []; var re = { constructor: null }; re[Symbol.match] = true; var p = new Proxy(re, { get: function(o, k) { get.push(k); return o[k]; }}); RegExp(p); return get[0] === Symbol.match && get.slice(1) + '' === "constructor,source,flags";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§RegExp.prototype.flags
?
function(){
// RegExp.prototype.flags -> Get -> [[Get]] var expected = []; // Sorted alphabetically by shortname – "gumsuy". if ('global' in RegExp.prototype) expected.push('global'); if ('ignoreCase' in RegExp.prototype) expected.push('ignoreCase'); if ('multiline' in RegExp.prototype) expected.push('multiline'); if ('dotAll' in RegExp.prototype) expected.push('dotAll'); if ('unicode' in RegExp.prototype) expected.push('unicode'); if ('sticky' in RegExp.prototype) expected.push('sticky'); var actual = []; var p = new Proxy({}, { get: function(o, k) { actual.push(k); return o[k]; }}); Object.getOwnPropertyDescriptor(RegExp.prototype, 'flags').get.call(p); if (expected.length !== actual.length) return false; for (var i = 0; i < expected.length; i++) { if (expected[i] !== actual[i]) return false; } return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§RegExp.prototype.test
?
function(){
// RegExp.prototype.test -> RegExpExec -> Get -> [[Get]] var get = []; var p = new Proxy({ exec: function() { return null; } }, { get: function(o, k) { get.push(k); return o[k]; }}); RegExp.prototype.test.call(p); return get + '' === "exec";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§RegExp.prototype.toString
?
function(){
// RegExp.prototype.toString -> Get -> [[Get]] var get = []; var p = new Proxy({}, { get: function(o, k) { get.push(k); return o[k]; }}); RegExp.prototype.toString.call(p); return get + '' === "source,flags";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§RegExp.prototype[Symbol.match]
?
function(){
// RegExp.prototype[Symbol.match] -> Get -> [[Get]] var get = []; var p = new Proxy({ exec: function() { return null; } }, { get: function(o, k) { get.push(k); return o[k]; }}); RegExp.prototype[Symbol.match].call(p); p.global = true; RegExp.prototype[Symbol.match].call(p); return get + '' === "global,exec,global,unicode,exec";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§RegExp.prototype[Symbol.replace]
?
function(){
// RegExp.prototype[Symbol.replace] -> Get -> [[Get]] var get = []; var p = new Proxy({ exec: function() { return null; } }, { get: function(o, k) { get.push(k); return o[k]; }}); RegExp.prototype[Symbol.replace].call(p); p.global = true; RegExp.prototype[Symbol.replace].call(p); return get + '' === "global,exec,global,unicode,exec";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§RegExp.prototype[Symbol.search]
?
function(){
// RegExp.prototype[Symbol.search] -> Get -> [[Get]] var get = []; var p = new Proxy({ exec: function() { return null; } }, { get: function(o, k) { get.push(k); return o[k]; }}); RegExp.prototype[Symbol.search].call(p); return get + '' === "lastIndex,exec,lastIndex";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§RegExp.prototype[Symbol.split]
?
function(){
// RegExp.prototype[Symbol.split] -> Get -> [[Get]] var get = []; var constructor = Function(); constructor[Symbol.species] = Object; var p = new Proxy({ constructor: constructor, flags: '', exec: function() { return null; } }, { get: function(o, k) { get.push(k); return o[k]; }}); RegExp.prototype[Symbol.split].call(p, ""); return get + '' === "constructor,flags,exec";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§Array.from
?
function(){
// Array.from -> Get -> [[Get]] var get = []; var p = new Proxy({length: 2, 0: '', 1: ''}, { get: function(o, k) { get.push(k); return o[k]; }}); Array.from(p); return get[0] === Symbol.iterator && get.slice(1) + '' === "length,0,1";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype.concat
?
function(){
// Array.prototype.concat -> Get -> [[Get]] var get = []; var arr = [1]; arr.constructor = undefined; var p = new Proxy(arr, { get: function(o, k) { get.push(k); return o[k]; }}); Array.prototype.concat.call(p,p); return get[0] === "constructor" && get[1] === Symbol.isConcatSpreadable && get[2] === "length" && get[3] === "0" && get[4] === get[1] && get[5] === get[2] && get[6] === get[3] && get.length === 7;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype iteration methods
?
function(){
// Array.prototype methods -> Get -> [[Get]] var methods = ['copyWithin', 'every', 'fill', 'filter', 'find', 'findIndex', 'forEach', 'indexOf', 'join', 'lastIndexOf', 'map', 'reduce', 'reduceRight', 'some']; var get; var p = new Proxy({length: 2, 0: '', 1: ''}, { get: function(o, k) { get.push(k); return o[k]; }}); for(var i = 0; i < methods.length; i+=1) { get = []; Array.prototype[methods[i]].call(p, Function()); if (get + '' !== ( methods[i] === 'fill' ? "length" : methods[i] === 'every' ? "length,0" : methods[i] === 'lastIndexOf' || methods[i] === 'reduceRight' ? "length,1,0" : "length,0,1" )) { return false; } } return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype.pop
?
function(){
// Array.prototype.pop -> Get -> [[Get]] var get = []; var p = new Proxy([0,1,2,3], { get: function(o, k) { get.push(k); return o[k]; }}); Array.prototype.pop.call(p); return get + '' === "length,3";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype.reverse
?
function(){
// Array.prototype.reverse -> Get -> [[Get]] var get = []; var p = new Proxy([0,,2,,4,,], { get: function(o, k) { get.push(k); return o[k]; }}); Array.prototype.reverse.call(p); return get + '' === "length,0,4,2";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype.shift
?
function(){
// Array.prototype.shift -> Get -> [[Get]] var get = []; var p = new Proxy([0,1,2,3], { get: function(o, k) { get.push(k); return o[k]; }}); Array.prototype.shift.call(p); return get + '' === "length,0,1,2,3";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype.splice
?
function(){
// Array.prototype.splice -> Get -> [[Get]] var get = []; var p = new Proxy([0,1,2,3], { get: function(o, k) { get.push(k); return o[k]; }}); Array.prototype.splice.call(p,1,1); Array.prototype.splice.call(p,1,0,1); return get + '' === "length,constructor,1,2,3,length,constructor,2,1";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype.toString
?
function(){
// Array.prototype.toString -> Get -> [[Get]] var get = []; var p = new Proxy({ join:Function() }, { get: function(o, k) { get.push(k); return o[k]; }}); Array.prototype.toString.call(p); return get + '' === "join";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§JSON.stringify
?
function(){
// JSON.stringify -> Get -> [[Get]] var get = []; var p = new Proxy({}, { get: function(o, k) { get.push(k); return o[k]; }}); JSON.stringify(p); return get + '' === "toJSON";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Promise resolve functions
?
function(){
// Promise resolve functions -> Get -> [[Get]] var get = []; var p = new Proxy({}, { get: function(o, k) { get.push(k); return o[k]; }}); new Promise(function(resolve){ resolve(p); }); return get + '' === "then";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§String.prototype.match
?
function(){
// String.prototype.match -> Get -> [[Get]] var get = []; var proxied = {}; proxied[Symbol.toPrimitive] = Function(); var p = new Proxy(proxied, { get: function(o, k) { get.push(k); return o[k]; }}); "".match(p); return get[0] === Symbol.match && get[1] === Symbol.toPrimitive && get.length === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error
Error
Error
Error
Error
Error
Error
§String.prototype.replace
?
function(){
// String.prototype.replace functions -> Get -> [[Get]] var get = []; var proxied = {}; proxied[Symbol.toPrimitive] = Function(); var p = new Proxy(proxied, { get: function(o, k) { get.push(k); return o[k]; }}); "".replace(p); return get[0] === Symbol.replace && get[1] === Symbol.toPrimitive && get.length === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§String.prototype.search
?
function(){
// String.prototype.search functions -> Get -> [[Get]] var get = []; var proxied = {}; proxied[Symbol.toPrimitive] = Function(); var p = new Proxy(proxied, { get: function(o, k) { get.push(k); return o[k]; }}); "".search(p); return get[0] === Symbol.search && get[1] === Symbol.toPrimitive && get.length === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error
Error
Error
Error
Error
Error
Error
§String.prototype.split
?
function(){
// String.prototype.split functions -> Get -> [[Get]] var get = []; var proxied = {}; proxied[Symbol.toPrimitive] = Function(); var p = new Proxy(proxied, { get: function(o, k) { get.push(k); return o[k]; }}); "".split(p); return get[0] === Symbol.split && get[1] === Symbol.toPrimitive && get.length === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Date.prototype.toJSON
?
function(){
// Date.prototype.toJSON -> ToPrimitive -> Get -> [[Get]] // Date.prototype.toJSON -> Invoke -> GetMethod -> GetV -> [[Get]] var get = []; var p = new Proxy({toString:Function(),toISOString:Function()}, { get: function(o, k) { get.push(k); return o[k]; }}); Date.prototype.toJSON.call(p); return get[0] === Symbol.toPrimitive && get.slice(1) + '' === "valueOf,toString,toISOString";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error

Proxy, internal 'set' calls

§Object.assign
?
function(){
// Object.assign -> Set -> [[Set]] var set = []; var p = new Proxy({}, { set: function(o, k, v) { set.push(k); o[k] = v; return true; }}); Object.assign(p, { foo: 1, bar: 2 }); return set + '' === "foo,bar";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.from
?
function(){
// Array.from -> Set -> [[Set]] var set = []; var p = new Proxy({}, { set: function(o, k, v) { set.push(k); o[k] = v; return true; }}); Array.from.call(function(){ return p; }, {length:2, 0:1, 1:2}); return set + '' === "length";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.of
?
function(){
// Array.from -> Set -> [[Set]] var set = []; var p = new Proxy({}, { set: function(o, k, v) { set.push(k); o[k] = v; return true; }}); Array.of.call(function(){ return p; }, 1, 2, 3); return set + '' === "length";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype.copyWithin
?
function(){
// Array.prototype.copyWithin -> Set -> [[Set]] var set = []; var p = new Proxy([1,2,3,4,5,6], { set: function(o, k, v) { set.push(k); o[k] = v; return true; }}); p.copyWithin(0, 3); return set + '' === "0,1,2";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype.fill
?
function(){
// Array.prototype.fill -> Set -> [[Set]] var set = []; var p = new Proxy([1,2,3,4,5,6], { set: function(o, k, v) { set.push(k); o[k] = v; return true; }}); p.fill(0, 3); return set + '' === "3,4,5";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype.pop
?
function(){
// Array.prototype.pop -> Set -> [[Set]] var set = []; var p = new Proxy([], { set: function(o, k, v) { set.push(k); o[k] = v; return true; }}); p.pop(); return set + '' === "length";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype.push
?
function(){
// Array.prototype.push -> Set -> [[Set]] var set = []; var p = new Proxy([], { set: function(o, k, v) { set.push(k); o[k] = v; return true; }}); p.push(0,0,0); return set + '' === "0,1,2,length";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype.reverse
?
function(){
// Array.prototype.reverse -> Set -> [[Set]] var set = []; var p = new Proxy([0,0,0,,], { set: function(o, k, v) { set.push(k); o[k] = v; return true; }}); p.reverse(); return set + '' === "3,1,2";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype.shift
?
function(){
// Array.prototype.shift -> Set -> [[Set]] var set = []; var p = new Proxy([0,0,,0], { set: function(o, k, v) { set.push(k); o[k] = v; return true; }}); p.shift(); return set + '' === "0,2,length";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype.splice
?
function(){
// Array.prototype.splice -> Set -> [[Set]] var set = []; var p = new Proxy([1,2,3], { set: function(o, k, v) { set.push(k); o[k] = v; return true; }}); p.splice(1,0,0); return set + '' === "3,2,1,length";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype.unshift
?
function(){
// Array.prototype.unshift -> Set -> [[Set]] var set = []; var p = new Proxy([0,0,,0], { set: function(o, k, v) { set.push(k); o[k] = v; return true; }}); p.unshift(0,1); return set + '' === "5,3,2,0,1,length";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error

Proxy, internal 'defineProperty' calls

§[[Set]]
?
function(){
// [[Set]] -> [[DefineOwnProperty]] var def = []; var p = new Proxy({foo:1, bar:2}, { defineProperty: function(o, v, desc) { def.push(v); Object.defineProperty(o, v, desc); return true; }}); p.foo = 2; p.bar = 4; return def + '' === "foo,bar";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§SetIntegrityLevel
?
function(){
// SetIntegrityLevel -> DefinePropertyOrThrow -> [[DefineOwnProperty]] var def = []; var p = new Proxy({foo:1, bar:2}, { defineProperty: function(o, v, desc) { def.push(v); Object.defineProperty(o, v, desc); return true; }}); Object.freeze(p); return def + '' === "foo,bar";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error

Proxy, internal 'deleteProperty' calls

§Array.prototype.copyWithin
?
function(){
// Array.prototype.copyWithin -> DeletePropertyOrThrow -> [[Delete]] var del = []; var p = new Proxy([0,0,0,,,,], { deleteProperty: function(o, v) { del.push(v); return delete o[v]; }}); p.copyWithin(0,3); return del + '' === "0,1,2";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype.pop
?
function(){
// Array.prototype.pop -> DeletePropertyOrThrow -> [[Delete]] var del = []; var p = new Proxy([0,0,0], { deleteProperty: function(o, v) { del.push(v); return delete o[v]; }}); p.pop(); return del + '' === "2";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype.reverse
?
function(){
// Array.prototype.reverse -> DeletePropertyOrThrow -> [[Delete]] var del = []; var p = new Proxy([0,,2,,4,,], { deleteProperty: function(o, v) { del.push(v); return delete o[v]; }}); p.reverse(); return del + '' === "0,4,2";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype.shift
?
function(){
// Array.prototype.shift -> DeletePropertyOrThrow -> [[Delete]] var del = []; var p = new Proxy([0,,0,,0,0], { deleteProperty: function(o, v) { del.push(v); return delete o[v]; }}); p.shift(); return del + '' === "0,2,5";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype.splice
?
function(){
// Array.prototype.splice -> DeletePropertyOrThrow -> [[Delete]] var del = []; var p = new Proxy([0,0,0,0,,0], { deleteProperty: function(o, v) { del.push(v); return delete o[v]; }}); p.splice(2,2,0); return del + '' === "3,5";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Array.prototype.unshift
?
function(){
// Array.prototype.unshift -> DeletePropertyOrThrow -> [[Delete]] var del = []; var p = new Proxy([0,0,,0,,0], { deleteProperty: function(o, v) { del.push(v); return delete o[v]; }}); p.unshift(0); return del + '' === "5,3";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error

Proxy, internal 'getOwnPropertyDescriptor' calls

§[[Set]]
?
function(){
// [[Set]] -> [[GetOwnProperty]] var gopd = []; var p = new Proxy({}, { getOwnPropertyDescriptor: function(o, v) { gopd.push(v); return Object.getOwnPropertyDescriptor(o, v); }}); p.foo = 1; p.bar = 1; return gopd + '' === "foo,bar";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Object.assign
?
function(){
// Object.assign -> [[GetOwnProperty]] var gopd = []; var p = new Proxy({foo:1, bar:2}, { getOwnPropertyDescriptor: function(o, v) { gopd.push(v); return Object.getOwnPropertyDescriptor(o, v); }}); Object.assign({}, p); return gopd + '' === "foo,bar";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Object.prototype.hasOwnProperty
?
function(){
// Object.prototype.hasOwnProperty -> HasOwnProperty -> [[GetOwnProperty]] var gopd = []; var p = new Proxy({foo:1, bar:2}, { getOwnPropertyDescriptor: function(o, v) { gopd.push(v); return Object.getOwnPropertyDescriptor(o, v); }}); p.hasOwnProperty('garply'); return gopd + '' === "garply";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Function.prototype.bind
?
function(){
// Function.prototype.bind -> HasOwnProperty -> [[GetOwnProperty]] var gopd = []; var p = new Proxy(Function(), { getOwnPropertyDescriptor: function(o, v) { gopd.push(v); return Object.getOwnPropertyDescriptor(o, v); }}); p.bind(); return gopd + '' === "length";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error

Proxy, internal 'ownKeys' calls

§SetIntegrityLevel
?
function(){
// SetIntegrityLevel -> [[OwnPropertyKeys]] var ownKeysCalled = 0; var p = new Proxy({}, { ownKeys: function(o) { ownKeysCalled++; return Object.keys(o); }}); Object.freeze(p); return ownKeysCalled === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§TestIntegrityLevel
?
function(){
// TestIntegrityLevel -> [[OwnPropertyKeys]] var ownKeysCalled = 0; var p = new Proxy(Object.preventExtensions({}), { ownKeys: function(o) { ownKeysCalled++; return Object.keys(o); }}); Object.isFrozen(p); return ownKeysCalled === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§SerializeJSONObject
?
function(){
// SerializeJSONObject -> EnumerableOwnNames -> [[OwnPropertyKeys]] var ownKeysCalled = 0; var p = new Proxy({}, { ownKeys: function(o) { ownKeysCalled++; return Object.keys(o); }}); JSON.stringify({a:p,b:p}); return ownKeysCalled === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error

Object static methods accept primitives

§Object.getPrototypeOf
?
function(){
return Object.getPrototypeOf('a').constructor === String;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§Object.getOwnPropertyDescriptor
?
function(){
return Object.getOwnPropertyDescriptor('a', 'foo') === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§Object.getOwnPropertyNames
?
function(){
var s = Object.getOwnPropertyNames('a'); return s.length === 2 && ((s[0] === 'length' && s[1] === '0') || (s[0] === '0' && s[1] === 'length'));
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§Object.seal
?
function(){
return Object.seal('a') === 'a';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§Object.freeze
?
function(){
return Object.freeze('a') === 'a';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§Object.preventExtensions
?
function(){
return Object.preventExtensions('a') === 'a';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§Object.isSealed
?
function(){
return Object.isSealed('a') === true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§Object.isFrozen
?
function(){
return Object.isFrozen('a') === true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§Object.isExtensible
?
function(){
return Object.isExtensible('a') === false;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§Object.keys
?
function(){
var s = Object.keys('a'); return s.length === 1 && s[0] === '0';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Error
Error
Error
Error

own property order

§Object.keys
?
function(){
var obj = { // Non-negative integer names appear first in value order 2: true, 0: true, 1: true, // Other string names appear in source order ' ': true, // Non-negative integers are sorted above other names 9: true, D: true, B: true, // Negative integers are treated as other names '-1': true, }; // Other string names are added in order of creation obj.A = true; // Non-negative integer names, conversely, ignore order of creation obj[3] = true; // Having a total of 20+ properties doesn't affect property order "EFGHIJKLMNOPQRSTUVWXYZ".split('').forEach(function(key){ obj[key] = true; }); // Object.defineProperty doesn't affect the above rules Object.defineProperty(obj, 'C', { value: true, enumerable: true }); Object.defineProperty(obj, '4', { value: true, enumerable: true }); // Deleting and reinserting a property doesn't preserve its position delete obj[2]; obj[2] = true; var forInOrder = ''; for(var key in obj)forInOrder += key; return Object.keys(obj).join('') === forInOrder;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§Object.getOwnPropertyNames
?
function(){
var obj = { 2: true, 0: true, 1: true, ' ': true, 9: true, D: true, B: true, '-1': true }; obj.A = true; obj[3] = true; "EFGHIJKLMNOPQRSTUVWXYZ".split('').forEach(function(key){ obj[key] = true; }); Object.defineProperty(obj, 'C', { value: true, enumerable: true }); Object.defineProperty(obj, '4', { value: true, enumerable: true }); delete obj[2]; obj[2] = true; return Object.getOwnPropertyNames(obj).join('') === "012349 DB-1AEFGHIJKLMNOPQRSTUVWXYZC";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
§Object.assign
?
function(){
var result = ''; var target = {}; "012349 DBACEFGHIJKLMNOPQRST".split('').concat(-1).forEach(function(key){ Object.defineProperty(target, key, { set: function(){ result += key; } }) }); var obj = {2: 2, 0: 0, 1: 1, ' ': ' ', 9: 9, D: 'D', B: 'B', '-1': '-1'}; Object.defineProperty(obj, 'A', {value: 'A', enumerable: true}); Object.defineProperty(obj, '3', {value: '3', enumerable: true}); Object.defineProperty(obj, 'C', {value: 'C', enumerable: true}); Object.defineProperty(obj, '4', {value: '4', enumerable: true}); delete obj[2]; obj[2] = true; "EFGHIJKLMNOPQRST".split('').forEach(function(key){ obj[key] = key; }); Object.assign(target, obj); return result === "012349 DB-1ACEFGHIJKLMNOPQRST";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Error
Error
Error
Error
§JSON.stringify
?
function(){
var obj = { 2: true, 0: true, 1: true, ' ': true, 9: true, D: true, B: true, '-1': true }; obj.A = true; obj[3] = true; "EFGHIJKLMNOPQRSTUVWXYZ".split('').forEach(function(key){ obj[key] = true; }); Object.defineProperty(obj, 'C', { value: true, enumerable: true }); Object.defineProperty(obj, '4', { value: true, enumerable: true }); delete obj[2]; obj[2] = true; return JSON.stringify(obj) === '{"0":true,"1":true,"2":true,"3":true,"4":true,"9":true," ":true,"D":true,"B":true,"-1":true,"A":true,"E":true,"F":true,"G":true,"H":true,"I":true,"J":true,"K":true,"L":true,"M":true,"N":true,"O":true,"P":true,"Q":true,"R":true,"S":true,"T":true,"U":true,"V":true,"W":true,"X":true,"Y":true,"Z":true,"C":true}';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
§JSON.parse
?
function(){
var result = ''; JSON.parse( '{"0":true,"1":true,"2":true,"3":true,"4":true,"9":true," ":true,"D":true,"B":true,"-1":true,"E":true,"F":true,"G":true,"H":true,"I":true,"J":true,"K":true,"L":true,"A":true,"C":true}', function reviver(k,v) { result += k; return v; } ); return result === "012349 DB-1EFGHIJKLAC";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§Reflect.ownKeys, string key order
?
function(){
var obj = { 2: true, 0: true, 1: true, ' ': true, 9: true, D: true, B: true, '-1': true }; obj.A = true; obj[3] = true; "EFGHIJKLMNOPQRSTUVWXYZ".split('').forEach(function(key){ obj[key] = true; }); Object.defineProperty(obj, 'C', { value: true, enumerable: true }); Object.defineProperty(obj, '4', { value: true, enumerable: true }); delete obj[2]; obj[2] = true; return Reflect.ownKeys(obj).join('') === "012349 DB-1AEFGHIJKLMNOPQRSTUVWXYZC";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§Reflect.ownKeys, symbol key order
?
function(){
var sym1 = Symbol(), sym2 = Symbol(), sym3 = Symbol(); var obj = { 1: true, A: true, }; obj.B = true; obj[sym1] = true; obj[2] = true; obj[sym2] = true; Object.defineProperty(obj, 'C', { value: true, enumerable: true }); Object.defineProperty(obj, sym3,{ value: true, enumerable: true }); Object.defineProperty(obj, 'D', { value: true, enumerable: true }); var result = Reflect.ownKeys(obj); var l = result.length; return result[l-3] === sym1 && result[l-2] === sym2 && result[l-1] === sym3;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error

Updated identifier syntax

§var ⸯ;
?
function(){
try { eval('var ⸯ'); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§var 𐋀;
?
function(){
var 𐋀; return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§no escaped reserved words as identifiers
?
function(){
var \u0061; try { eval('var v\\u0061r'); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No

miscellaneous

§duplicate property names in strict mode
?
function(){
'use strict'; return this === undefined && ({ a:1, a:1 }).a === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§no semicolon needed after do-while
?
function(){
do {} while (false) return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§no assignments allowed in for-in head in strict mode
?
function(){
'use strict'; try { eval('for (var i = 0 in {}) {}'); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§accessors aren't constructors
?
function(){
var f = (Object.getOwnPropertyDescriptor({get a(){}}, 'a')).get; try { new f; } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
§Invalid Date
?
function(){
return new Date(NaN) + "" === "Invalid Date";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§RegExp constructor can alter flags
?
function(){
return new RegExp(/./im, "g").global === true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§RegExp.prototype.toString generic and uses "flags" property
?
function(){
return RegExp.prototype.toString.call({source: 'foo', flags: 'bar'}) === '/foo/bar';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§built-in prototypes are not instances
?
function(){
try { RegExp.prototype.exec(); return false; } catch(e) {} try { Date.prototype.valueOf(); return false; } catch(e) {} if (![Error, EvalError, RangeError, ReferenceError, SyntaxError, TypeError, URIError].every(function (E) { return Object.prototype.toString.call(E.prototype) === '[object Object]'; })) { return false; } return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
§function 'length' is configurable
?
function(){
var fn = function(a, b) {}; var desc = Object.getOwnPropertyDescriptor(fn, "length"); if (desc.configurable) { Object.defineProperty(fn, "length", { value: 1 }); return fn.length === 1; } return false;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No

annex b

non-strict function semantics

§hoisted block-level function declaration
?
function(){
// Note: only available outside of strict mode. if (!this) return false; var passed = f() === 1; function f() { return 1; } passed &= typeof g === 'undefined'; { function g() { return 1; } } passed &= g() === 1; passed &= h() === 2; { function h() { return 1; } } function h() { return 2; } passed &= h() === 1; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Error
No
Error
No
§labeled function statements
?
function(){
// Note: only available outside of strict mode. if (!this) return false; label: function foo() { return 2; } return foo() === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§function statements in if-statement clauses
?
function(){
// Note: only available outside of strict mode. if (!this) return false; if(true) function foo() { return 2; } if(false) {} else function bar() { return 3; } if(true) function baz() { return 4; } else {} if(false) function qux() { return 5; } else function qux() { return 6; } return foo() === 2 && bar() === 3 && baz() === 4 && qux() === 6;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes

__proto__ in object literals

§basic support
?
function(){
return { __proto__ : [] } instanceof Array && !({ __proto__ : null } instanceof Object);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§multiple __proto__ is an error
?
function(){
try { eval("({ __proto__ : [], __proto__: {} })"); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
§not a computed property
?
function(){
if (!({ __proto__ : [] } instanceof Array)) { return false; } var a = "__proto__"; return !({ [a] : [] } instanceof Array);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§not a shorthand property
?
function(){
if (!({ __proto__ : [] } instanceof Array)) { return false; } var __proto__ = []; return !({ __proto__ } instanceof Array);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
§not a shorthand method
?
function(){
if (!({ __proto__ : [] } instanceof Array)) { return false; } return !({ __proto__(){} } instanceof Function);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error

Object.prototype.__proto__

§get prototype
?
function(){
var A = function(){}; return (new A()).__proto__ === A.prototype;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§set prototype
?
function(){
var o = {}; o.__proto__ = Array.prototype; return o instanceof Array;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§absent from Object.create(null)
?
function(){
var o = Object.create(null), p = {}; o.__proto__ = p; return Object.getPrototypeOf(o) !== p;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§present in hasOwnProperty()
?
function(){
return Object.prototype.hasOwnProperty('__proto__');
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§correct property descriptor
?
function(){
var desc = Object.getOwnPropertyDescriptor(Object.prototype,"__proto__"); var A = function(){}; return (desc && "get" in desc && "set" in desc && desc.configurable && !desc.enumerable);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
§present in Object.getOwnPropertyNames()
?
function(){
return Object.getOwnPropertyNames(Object.prototype).indexOf('__proto__') > -1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No

String.prototype HTML methods

§existence
?
function(){
var i, names = ["anchor", "big", "bold", "fixed", "fontcolor", "fontsize", "italics", "link", "small", "strike", "sub", "sup"]; for (i = 0; i < names.length; i++) { if (typeof String.prototype[names[i]] !== 'function') { return false; } } return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§tags' names are lowercase
?
function(){
var i, names = ["anchor", "big", "bold", "fixed", "fontcolor", "fontsize", "italics", "link", "small", "strike", "sub", "sup"]; for (i = 0; i < names.length; i++) { if (""[names[i]]().toLowerCase() !== ""[names[i]]()) { return false; } } return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§quotes in arguments are escaped
?
function(){
var i, names = ["anchor", "fontcolor", "fontsize", "link"]; for (i = 0; i < names.length; i++) { if (""[names[i]]('"') !== ""[names[i]]('&' + 'quot;')) { return false; } } return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes

RegExp.prototype.compile

§basic functionality
?
function(){
if (typeof RegExp.prototype.compile !== 'function') return false var rx = /a/; rx.compile('b'); return rx.test('b');
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§returns this
?
function(){
var rx = /a/; return rx.compile('b') === rx;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No

RegExp syntax extensions

§hyphens in character sets
?
function(){
return /[\w-_]/.exec("-")[0] === "-";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§invalid character escapes
?
function(){
return /\z/.exec("\\z")[0] === "z" && /[\z]/.exec("[\\z]")[0] === "z";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§invalid control-character escapes
?
function(){
return /\c2/.exec("\\c2")[0] === "\\c2";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§invalid Unicode escapes
?
function(){
return /\u1/.exec("u1")[0] === "u1" && /[\u1]/.exec("u")[0] === "u";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§invalid hexadecimal escapes
?
function(){
return /\x1/.exec("x1")[0] === "x1" && /[\x1]/.exec("x")[0] === "x";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§incomplete patterns and quantifiers
?
function(){
return /x{1/.exec("x{1")[0] === "x{1" && /x]1/.exec("x]1")[0] === "x]1";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§octal escape sequences
?
function(){
return /\041/.exec("!")[0] === "!" && /[\041]/.exec("!")[0] === "!";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§invalid backreferences become octal escapes
?
function(){
return /\41/.exec("!")[0] === "!" && /[\41]/.exec("!")[0] === "!";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes

§HTML-style comments
?
function(){
--> A comment <!-- Another comment var a = 3; <!-- Another comment return a === 3;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes

Node.js ES2016 Support

14.0.0
(these versions have identical results)
nightly v8 7.8.279.17-node.19
Nightly!100% complete100% complete 		13.0.1
(these versions have identical results)
13.0.1 v8 7.8.279.17-node.14
13.0.0 v8 7.8.279.17-node.14
12.13.0 v8 7.7.299.13-node.12
12.12.0 v8 7.7.299.13-node.12
12.11.1 v8 7.7.299.11-node.12
12.11.0 v8 7.7.299.11-node.12
100% complete100% complete 		12.10.0
(these versions have identical results)
12.10.0 v8 7.6.303.29-node.16
12.9.1 v8 7.6.303.29-node.15
12.9.0 v8 7.6.303.29-node.15
100% complete100% complete 		12.8.1
(these versions have identical results)
12.8.1 v8 7.5.288.22-node.16
12.8.0 v8 7.5.288.22-node.16
12.7.0 v8 7.5.288.22-node.16
12.6.0 v8 7.5.288.22-node.14
12.5.0 v8 7.5.288.22-node.14
100% complete100% complete 		12.4.0
(these versions have identical results)
12.4.0 v8 7.4.288.27-node.18
12.3.1 v8 7.4.288.27-node.18
12.3.0 v8 7.4.288.27-node.17
12.2.0 v8 7.4.288.21-node.17
12.1.0 v8 7.4.288.21-node.16
12.0.0 v8 7.4.288.21-node.16
100% complete100% complete 		11.15.0
(these versions have identical results)
11.15.0 v8 7.0.276.38-node.19
11.14.0 v8 7.0.276.38-node.18
11.13.0 v8 7.0.276.38-node.18
11.12.0 v8 7.0.276.38-node.18
11.11.0 v8 7.0.276.38-node.18
11.10.1 v8 7.0.276.38-node.17
11.10.0 v8 7.0.276.38-node.17
11.9.0 v8 7.0.276.38-node.16
11.8.0 v8 7.0.276.38-node.16
11.7.0 v8 7.0.276.38-node.16
11.6.0 v8 7.0.276.38-node.13
11.5.0 v8 7.0.276.38-node.13
11.4.0 v8 7.0.276.38-node.13
11.3.0 v8 7.0.276.38-node.11
11.2.0 v8 7.0.276.38-node.11
11.1.0 v8 7.0.276.32-node.7
11.0.0 v8 7.0.276.28-node.5
100% complete100% complete 		10.17.0
(these versions have identical results)
10.17.0 v8 6.8.275.32-node.54
10.16.3 v8 6.8.275.32-node.54
10.16.2 v8 6.8.275.32-node.54
10.16.1 v8 6.8.275.32-node.54
10.16.0 v8 6.8.275.32-node.52
10.15.3 v8 6.8.275.32-node.51
10.15.2 v8 6.8.275.32-node.12
10.15.1 v8 6.8.275.32-node.12
10.15.0 v8 6.8.275.32-node.45
10.14.2 v8 6.8.275.32-node.45
10.14.1 v8 6.8.275.32-node.36
10.14.0 v8 6.8.275.32-node.36
10.13.0 v8 6.8.275.32-node.36
10.12.0 v8 6.8.275.32-node.35
10.11.0 v8 6.8.275.32-node.28
10.10.0 v8 6.8.275.30-node.24
10.9.0 v8 6.8.275.24-node.14
100% complete100% complete 		10.8.0
(these versions have identical results)
10.8.0 v8 6.7.288.49-node.19
10.7.0 v8 6.7.288.49-node.15
10.6.0 v8 6.7.288.46-node.13
10.5.0 v8 6.7.288.46-node.8
10.4.1 v8 6.7.288.45-node.7
10.4.0 v8 6.7.288.43-node.7
100% complete100% complete 		10.3.0
(these versions have identical results)
10.3.0 v8 6.6.346.32-node.9
10.2.1 v8 6.6.346.32-node.8
10.2.0 v8 6.6.346.32-node.8
10.1.0 v8 6.6.346.27-node.6
10.0.0 v8 6.6.346.24-node.5
100% complete100% complete 		9.11.2
(these versions have identical results)
9.11.2 v8 6.2.414.46-node.23
9.11.1 v8 6.2.414.46-node.23
9.11.0 v8 6.2.414.46-node.23
9.10.1 v8 6.2.414.46-node.23
9.10.0 v8 6.2.414.46-node.23
9.9.0 v8 6.2.414.46-node.22
9.8.0 v8 6.2.414.46-node.21
9.7.1 v8 6.2.414.46-node.20
9.7.0 v8 6.2.414.46-node.20
9.6.1 v8 6.2.414.46-node.20
9.6.0 v8 6.2.414.46-node.20
9.5.0 v8 6.2.414.46-node.18
9.4.0 v8 6.2.414.46-node.17
9.3.0 v8 6.2.414.46-node.15
9.2.1 v8 6.2.414.44-node.11
9.2.0 v8 6.2.414.44-node.11
9.1.0 v8 6.2.414.32-node.8
9.0.0 v8 6.2.414.32-node.8
8.16.2 v8 6.2.414.78
8.16.1 v8 6.2.414.77
8.16.0 v8 6.2.414.77
8.15.1 v8 6.2.414.75
8.15.0 v8 6.2.414.75
8.14.1 v8 6.2.414.75
8.14.0 v8 6.2.414.72
8.13.0 v8 6.2.414.72
8.12.0 v8 6.2.414.66
8.11.4 v8 6.2.414.54
8.11.3 v8 6.2.414.54
8.11.2 v8 6.2.414.54
8.11.1 v8 6.2.414.50
8.11.0 v8 6.2.414.50
8.10.0 v8 6.2.414.50
100% complete100% complete 		8.9.4
(these versions have identical results)
8.9.4 v8 6.1.534.50
8.9.3 v8 6.1.534.48
8.9.2 v8 6.1.534.48
8.9.1 v8 6.1.534.47
8.9.0 v8 6.1.534.46
8.8.1 v8 6.1.534.42
8.8.0 v8 6.1.534.42
8.7.0 v8 6.1.534.42
100% complete100% complete 		8.6.0
(these versions have identical results)
8.6.0 v8 6.0.287.53
8.5.0 v8 6.0.287.53
8.4.0 v8 6.0.286.52
8.3.0 v8 6.0.286.52
100% complete100% complete 		8.2.1
(these versions have identical results)
8.2.1 v8 5.8.283.41
8.2.0 v8 5.8.283.41
8.1.4 v8 5.8.283.41
8.1.3 v8 5.8.283.41
8.1.2 v8 5.8.283.41
8.1.1 v8 5.8.283.41
8.1.0 v8 5.8.283.41
8.0.0 v8 5.8.283.41
100% complete100% complete 		7.10.1
(these versions have identical results)
7.10.1 v8 5.5.372.43
7.10.0 v8 5.5.372.43
7.9.0 v8 5.5.372.43
7.8.0 v8 5.5.372.43
7.7.4 v8 5.5.372.42
7.7.3 v8 5.5.372.41
7.7.2 v8 5.5.372.41
7.7.1 v8 5.5.372.41
7.7.0 v8 5.5.372.41
7.6.0 v8 5.5.372.40
100% complete100% complete 		7.5.0
(these versions have identical results)
7.5.0 v8 5.4.500.48
7.4.0 v8 5.4.500.45
7.3.0 v8 5.4.500.45
7.2.1 v8 5.4.500.44
7.2.0 v8 5.4.500.43
7.1.0 v8 5.4.500.36
7.0.0 v8 5.4.500.36
100% complete100% complete 		6.17.1
(these versions have identical results)
6.17.1 v8 5.1.281.111
6.17.0 v8 5.1.281.111
6.16.0 v8 5.1.281.111
6.15.1 v8 5.1.281.111
6.15.0 v8 5.1.281.111
6.14.4 v8 5.1.281.111
6.14.3 v8 5.1.281.111
6.14.2 v8 5.1.281.111
6.14.1 v8 5.1.281.111
6.14.0 v8 5.1.281.111
6.13.1 v8 5.1.281.111
6.13.0 v8 5.1.281.111
6.12.3 v8 5.1.281.111
6.12.2 v8 5.1.281.109
6.12.1 v8 5.1.281.109
6.12.0 v8 5.1.281.108
6.11.5 v8 5.1.281.108
6.11.4 v8 5.1.281.108
6.11.3 v8 5.1.281.107
6.11.2 v8 5.1.281.103
6.11.1 v8 5.1.281.103
6.11.0 v8 5.1.281.102
6.10.3 v8 5.1.281.101
6.10.2 v8 5.1.281.98
6.10.1 v8 5.1.281.95
6.10.0 v8 5.1.281.93
6.9.5 v8 5.1.281.89
6.9.4 v8 5.1.281.89
6.9.3 v8 5.1.281.89
6.9.2 v8 5.1.281.88
6.9.1 v8 5.1.281.84
6.9.0 v8 5.1.281.84
6.8.1 v8 5.1.281.84
6.8.0 v8 5.1.281.84
6.7.0 v8 5.1.281.83
6.6.0 v8 5.1.281.83
6.5.0 v8 5.1.281.81
100% complete76% complete 		6.4.0
(these versions have identical results)
6.4.0 v8 5.0.71.60
6.3.1 v8 5.0.71.57
6.3.0 v8 5.0.71.52
6.2.2 v8 5.0.71.52
6.2.1 v8 5.0.71.52
6.2.0 v8 5.0.71.47
6.1.0 v8 5.0.71.35
6.0.0 v8 5.0.71.35
76% complete76% complete 		5.12.0
(these versions have identical results)
5.12.0 v8 4.6.85.32
5.11.1 v8 4.6.85.31
5.11.0 v8 4.6.85.31
5.10.1 v8 4.6.85.31
5.10.0 v8 4.6.85.31
5.9.1 v8 4.6.85.31
5.9.0 v8 4.6.85.31
5.8.0 v8 4.6.85.31
5.7.1 v8 4.6.85.31
5.7.0 v8 4.6.85.31
5.6.0 v8 4.6.85.31
5.5.0 v8 4.6.85.31
5.4.1 v8 4.6.85.31
5.4.0 v8 4.6.85.31
5.3.0 v8 4.6.85.31
5.2.0 v8 4.6.85.31
5.1.1 v8 4.6.85.31
5.1.0 v8 4.6.85.31
5.0.0 v8 4.6.85.28
30% complete7% complete 		4.9.1
(these versions have identical results)
4.9.1 v8 4.5.103.53
4.9.0 v8 4.5.103.53
4.8.7 v8 4.5.103.53
4.8.6 v8 4.5.103.53
4.8.5 v8 4.5.103.47
4.8.4 v8 4.5.103.47
4.8.3 v8 4.5.103.47
4.8.2 v8 4.5.103.46
4.8.1 v8 4.5.103.46
4.8.0 v8 4.5.103.45
4.7.3 v8 4.5.103.43
4.7.2 v8 4.5.103.43
4.7.1 v8 4.5.103.43
4.7.0 v8 4.5.103.43
4.6.2 v8 4.5.103.42
4.6.1 v8 4.5.103.37
4.6.0 v8 4.5.103.37
4.5.0 v8 4.5.103.37
4.4.7 v8 4.5.103.36
4.4.6 v8 4.5.103.36
4.4.5 v8 4.5.103.35
4.4.4 v8 4.5.103.35
4.4.3 v8 4.5.103.35
4.4.2 v8 4.5.103.35
4.4.1 v8 4.5.103.35
4.4.0 v8 4.5.103.35
4.3.2 v8 4.5.103.35
4.3.1 v8 4.5.103.35
4.3.0 v8 4.5.103.35
4.2.6 v8 4.5.103.35
4.2.5 v8 4.5.103.35
4.2.4 v8 4.5.103.35
4.2.3 v8 4.5.103.35
4.2.2 v8 4.5.103.35
4.2.1 v8 4.5.103.35
4.2.0 v8 4.5.103.35
4.1.2 v8 4.5.103.35
4.1.1 v8 4.5.103.33
4.1.0 v8 4.5.103.33
4.0.0 v8 4.5.103.30
7% complete7% complete 		0.12.18
(these versions have identical results)
0.12.18 v8 3.28.71.20
7% complete0% complete 		0.10.48
(these versions have identical results)
0.10.48 v8 3.14.5.11
0% complete0% complete

features

exponentiation (**) operator

§basic support
?
function(){
return 2 ** 3 === 8 && -(5 ** 2) === -25 && (-5) ** 2 === 25;
}
Yes
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§assignment
?
function(){
var a = 2; a **= 3; return a === 8;
}
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Error
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§early syntax error for unary negation without parens
?
function(){
if (2 ** 3 !== 8) { return false; } try { Function("-5 ** 2")(); } catch(e) { return true; }
}
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Array.prototype.includes

§Array.prototype.includes
?
function(){
return [1, 2, 3].includes(1) && ![1, 2, 3].includes(4) && ![1, 2, 3].includes(1, 1) && [NaN].includes(NaN) && Array(1).includes();
}
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§Array.prototype.includes is generic
?
function(){
var passed = 0; return [].includes.call({ get "0"() { passed = NaN; return 'foo'; }, get "11"() { passed += 1; return 0; }, get "19"() { passed += 1; return 'foo'; }, get "21"() { passed = NaN; return 'foo'; }, get length() { passed += 1; return 24; } }, 'foo', 6) === true && passed === 3;
}
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§%TypedArray%.prototype.includes
?
function(){
return [Int8Array, Uint8Array, Uint8ClampedArray, Int16Array, Uint16Array, Int32Array, Uint32Array, Float32Array, Float64Array].every(function(TypedArray){ return new TypedArray([1, 2, 3]).includes(1) && !new TypedArray([1, 2, 3]).includes(4) && !new TypedArray([1, 2, 3]).includes(1, 1); });
}
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Error

misc

§generator functions can't be used with "new"
?
function(){
function * generator() { yield 3; } try { new generator(); } catch(e) { return true; }
}
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§generator throw() caught by inner generator
?
function(){
function * generator() { yield * (function * () { try { yield 'foo'; } catch(e) { return; } }()); yield 'bar'; } var iter = generator(); iter.next(); return iter['throw']().value === 'bar';
}
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Error
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§strict fn w/ non-strict non-simple params is error
?
function(){
function foo(...a){} try { Function("function bar(...a){'use strict';}")(); } catch(e) { return true; }
}
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§nested rest destructuring, declarations
?
function(){
var [x, ...[y, ...z]] = [1,2,3,4]; return x === 1 && y === 2 && z + '' === '3,4';
}
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§nested rest destructuring, parameters
?
function(){
return function([x, ...[y, ...z]]) { return x === 1 && y === 2 && z + '' === '3,4'; }([1,2,3,4]);
}
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§Proxy, "enumerate" handler removed
?
function(){
var passed = true; var proxy = new Proxy({}, { enumerate: function() { passed = false; } }); for(var key in proxy); // Should not throw, nor execute the 'enumerate' method. return passed;
}
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§Proxy internal calls, Array.prototype.includes
?
function(){
// Array.prototype.includes -> Get -> [[Get]] var get = []; var p = new Proxy({length: 3, 0: '', 1: '', 2: '', 3: ''}, { get: function(o, k) { get.push(k); return o[k]; }}); Array.prototype.includes.call(p, {}); if (get + '' !== "length,0,1,2") return; get = []; p = new Proxy({length: 4, 0: NaN, 1: '', 2: NaN, 3: ''}, { get: function(o, k) { get.push(k); return o[k]; }}); Array.prototype.includes.call(p, NaN, 1); return (get + '' === "length,1,2");
}
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Node.js ES2017 Support

14.0.0
(these versions have identical results)
nightly v8 7.8.279.17-node.19
Nightly!96% complete96% complete 		13.0.1
(these versions have identical results)
13.0.1 v8 7.8.279.17-node.14
13.0.0 v8 7.8.279.17-node.14
12.13.0 v8 7.7.299.13-node.12
12.12.0 v8 7.7.299.13-node.12
12.11.1 v8 7.7.299.11-node.12
12.11.0 v8 7.7.299.11-node.12
96% complete96% complete 		12.10.0
(these versions have identical results)
12.10.0 v8 7.6.303.29-node.16
12.9.1 v8 7.6.303.29-node.15
12.9.0 v8 7.6.303.29-node.15
98% complete98% complete 		12.8.1
(these versions have identical results)
12.8.1 v8 7.5.288.22-node.16
12.8.0 v8 7.5.288.22-node.16
12.7.0 v8 7.5.288.22-node.16
12.6.0 v8 7.5.288.22-node.14
12.5.0 v8 7.5.288.22-node.14
98% complete98% complete 		12.4.0
(these versions have identical results)
12.4.0 v8 7.4.288.27-node.18
12.3.1 v8 7.4.288.27-node.18
12.3.0 v8 7.4.288.27-node.17
12.2.0 v8 7.4.288.21-node.17
12.1.0 v8 7.4.288.21-node.16
12.0.0 v8 7.4.288.21-node.16
96% complete96% complete 		11.15.0
(these versions have identical results)
11.15.0 v8 7.0.276.38-node.19
11.14.0 v8 7.0.276.38-node.18
11.13.0 v8 7.0.276.38-node.18
11.12.0 v8 7.0.276.38-node.18
11.11.0 v8 7.0.276.38-node.18
11.10.1 v8 7.0.276.38-node.17
11.10.0 v8 7.0.276.38-node.17
11.9.0 v8 7.0.276.38-node.16
11.8.0 v8 7.0.276.38-node.16
11.7.0 v8 7.0.276.38-node.16
11.6.0 v8 7.0.276.38-node.13
11.5.0 v8 7.0.276.38-node.13
11.4.0 v8 7.0.276.38-node.13
11.3.0 v8 7.0.276.38-node.11
11.2.0 v8 7.0.276.38-node.11
11.1.0 v8 7.0.276.32-node.7
11.0.0 v8 7.0.276.28-node.5
100% complete100% complete 		10.17.0
(these versions have identical results)
10.17.0 v8 6.8.275.32-node.54
10.16.3 v8 6.8.275.32-node.54
10.16.2 v8 6.8.275.32-node.54
10.16.1 v8 6.8.275.32-node.54
10.16.0 v8 6.8.275.32-node.52
10.15.3 v8 6.8.275.32-node.51
10.15.2 v8 6.8.275.32-node.12
10.15.1 v8 6.8.275.32-node.12
10.15.0 v8 6.8.275.32-node.45
10.14.2 v8 6.8.275.32-node.45
10.14.1 v8 6.8.275.32-node.36
10.14.0 v8 6.8.275.32-node.36
10.13.0 v8 6.8.275.32-node.36
10.12.0 v8 6.8.275.32-node.35
10.11.0 v8 6.8.275.32-node.28
10.10.0 v8 6.8.275.30-node.24
10.9.0 v8 6.8.275.24-node.14
100% complete100% complete 		10.8.0
(these versions have identical results)
10.8.0 v8 6.7.288.49-node.19
10.7.0 v8 6.7.288.49-node.15
10.6.0 v8 6.7.288.46-node.13
10.5.0 v8 6.7.288.46-node.8
10.4.1 v8 6.7.288.45-node.7
10.4.0 v8 6.7.288.43-node.7
100% complete100% complete 		10.3.0
(these versions have identical results)
10.3.0 v8 6.6.346.32-node.9
10.2.1 v8 6.6.346.32-node.8
10.2.0 v8 6.6.346.32-node.8
10.1.0 v8 6.6.346.27-node.6
10.0.0 v8 6.6.346.24-node.5
100% complete100% complete 		9.11.2
(these versions have identical results)
9.11.2 v8 6.2.414.46-node.23
9.11.1 v8 6.2.414.46-node.23
9.11.0 v8 6.2.414.46-node.23
9.10.1 v8 6.2.414.46-node.23
9.10.0 v8 6.2.414.46-node.23
9.9.0 v8 6.2.414.46-node.22
9.8.0 v8 6.2.414.46-node.21
9.7.1 v8 6.2.414.46-node.20
9.7.0 v8 6.2.414.46-node.20
9.6.1 v8 6.2.414.46-node.20
9.6.0 v8 6.2.414.46-node.20
9.5.0 v8 6.2.414.46-node.18
9.4.0 v8 6.2.414.46-node.17
9.3.0 v8 6.2.414.46-node.15
9.2.1 v8 6.2.414.44-node.11
9.2.0 v8 6.2.414.44-node.11
9.1.0 v8 6.2.414.32-node.8
9.0.0 v8 6.2.414.32-node.8
8.16.2 v8 6.2.414.78
8.16.1 v8 6.2.414.77
8.16.0 v8 6.2.414.77
8.15.1 v8 6.2.414.75
8.15.0 v8 6.2.414.75
8.14.1 v8 6.2.414.75
8.14.0 v8 6.2.414.72
8.13.0 v8 6.2.414.72
8.12.0 v8 6.2.414.66
8.11.4 v8 6.2.414.54
8.11.3 v8 6.2.414.54
8.11.2 v8 6.2.414.54
8.11.1 v8 6.2.414.50
8.11.0 v8 6.2.414.50
8.10.0 v8 6.2.414.50
100% complete100% complete 		8.9.4
(these versions have identical results)
8.9.4 v8 6.1.534.50
8.9.3 v8 6.1.534.48
8.9.2 v8 6.1.534.48
8.9.1 v8 6.1.534.47
8.9.0 v8 6.1.534.46
8.8.1 v8 6.1.534.42
8.8.0 v8 6.1.534.42
8.7.0 v8 6.1.534.42
73% complete67% complete 		8.6.0
(these versions have identical results)
8.6.0 v8 6.0.287.53
8.5.0 v8 6.0.287.53
8.4.0 v8 6.0.286.52
8.3.0 v8 6.0.286.52
73% complete67% complete 		8.2.1
(these versions have identical results)
8.2.1 v8 5.8.283.41
8.2.0 v8 5.8.283.41
8.1.4 v8 5.8.283.41
8.1.3 v8 5.8.283.41
8.1.2 v8 5.8.283.41
8.1.1 v8 5.8.283.41
8.1.0 v8 5.8.283.41
8.0.0 v8 5.8.283.41
66% complete66% complete 		7.10.1
(these versions have identical results)
7.10.1 v8 5.5.372.43
7.10.0 v8 5.5.372.43
7.9.0 v8 5.5.372.43
7.8.0 v8 5.5.372.43
7.7.4 v8 5.5.372.42
7.7.3 v8 5.5.372.41
7.7.2 v8 5.5.372.41
7.7.1 v8 5.5.372.41
7.7.0 v8 5.5.372.41
7.6.0 v8 5.5.372.40
55% complete52% complete 		7.5.0
(these versions have identical results)
7.5.0 v8 5.4.500.48
7.4.0 v8 5.4.500.45
7.3.0 v8 5.4.500.45
7.2.1 v8 5.4.500.44
7.2.0 v8 5.4.500.43
7.1.0 v8 5.4.500.36
7.0.0 v8 5.4.500.36
55% complete27% complete 		6.17.1
(these versions have identical results)
6.17.1 v8 5.1.281.111
6.17.0 v8 5.1.281.111
6.16.0 v8 5.1.281.111
6.15.1 v8 5.1.281.111
6.15.0 v8 5.1.281.111
6.14.4 v8 5.1.281.111
6.14.3 v8 5.1.281.111
6.14.2 v8 5.1.281.111
6.14.1 v8 5.1.281.111
6.14.0 v8 5.1.281.111
6.13.1 v8 5.1.281.111
6.13.0 v8 5.1.281.111
6.12.3 v8 5.1.281.111
6.12.2 v8 5.1.281.109
6.12.1 v8 5.1.281.109
6.12.0 v8 5.1.281.108
6.11.5 v8 5.1.281.108
6.11.4 v8 5.1.281.108
6.11.3 v8 5.1.281.107
6.11.2 v8 5.1.281.103
6.11.1 v8 5.1.281.103
6.11.0 v8 5.1.281.102
6.10.3 v8 5.1.281.101
6.10.2 v8 5.1.281.98
6.10.1 v8 5.1.281.95
6.10.0 v8 5.1.281.93
6.9.5 v8 5.1.281.89
6.9.4 v8 5.1.281.89
6.9.3 v8 5.1.281.89
6.9.2 v8 5.1.281.88
6.9.1 v8 5.1.281.84
6.9.0 v8 5.1.281.84
6.8.1 v8 5.1.281.84
6.8.0 v8 5.1.281.84
6.7.0 v8 5.1.281.83
6.6.0 v8 5.1.281.83
6.5.0 v8 5.1.281.81
23% complete18% complete 		6.4.0
(these versions have identical results)
6.4.0 v8 5.0.71.60
6.3.1 v8 5.0.71.57
6.3.0 v8 5.0.71.52
6.2.2 v8 5.0.71.52
6.2.1 v8 5.0.71.52
6.2.0 v8 5.0.71.47
6.1.0 v8 5.0.71.35
6.0.0 v8 5.0.71.35
18% complete18% complete 		5.12.0
(these versions have identical results)
5.12.0 v8 4.6.85.32
5.11.1 v8 4.6.85.31
5.11.0 v8 4.6.85.31
5.10.1 v8 4.6.85.31
5.10.0 v8 4.6.85.31
5.9.1 v8 4.6.85.31
5.9.0 v8 4.6.85.31
5.8.0 v8 4.6.85.31
5.7.1 v8 4.6.85.31
5.7.0 v8 4.6.85.31
5.6.0 v8 4.6.85.31
5.5.0 v8 4.6.85.31
5.4.1 v8 4.6.85.31
5.4.0 v8 4.6.85.31
5.3.0 v8 4.6.85.31
5.2.0 v8 4.6.85.31
5.1.1 v8 4.6.85.31
5.1.0 v8 4.6.85.31
5.0.0 v8 4.6.85.28
16% complete16% complete 		4.9.1
(these versions have identical results)
4.9.1 v8 4.5.103.53
4.9.0 v8 4.5.103.53
4.8.7 v8 4.5.103.53
4.8.6 v8 4.5.103.53
4.8.5 v8 4.5.103.47
4.8.4 v8 4.5.103.47
4.8.3 v8 4.5.103.47
4.8.2 v8 4.5.103.46
4.8.1 v8 4.5.103.46
4.8.0 v8 4.5.103.45
4.7.3 v8 4.5.103.43
4.7.2 v8 4.5.103.43
4.7.1 v8 4.5.103.43
4.7.0 v8 4.5.103.43
4.6.2 v8 4.5.103.42
4.6.1 v8 4.5.103.37
4.6.0 v8 4.5.103.37
4.5.0 v8 4.5.103.37
4.4.7 v8 4.5.103.36
4.4.6 v8 4.5.103.36
4.4.5 v8 4.5.103.35
4.4.4 v8 4.5.103.35
4.4.3 v8 4.5.103.35
4.4.2 v8 4.5.103.35
4.4.1 v8 4.5.103.35
4.4.0 v8 4.5.103.35
4.3.2 v8 4.5.103.35
4.3.1 v8 4.5.103.35
4.3.0 v8 4.5.103.35
4.2.6 v8 4.5.103.35
4.2.5 v8 4.5.103.35
4.2.4 v8 4.5.103.35
4.2.3 v8 4.5.103.35
4.2.2 v8 4.5.103.35
4.2.1 v8 4.5.103.35
4.2.0 v8 4.5.103.35
4.1.2 v8 4.5.103.35
4.1.1 v8 4.5.103.33
4.1.0 v8 4.5.103.33
4.0.0 v8 4.5.103.30
16% complete16% complete 		0.12.18
(these versions have identical results)
0.12.18 v8 3.28.71.20
16% complete17% complete 		0.10.48
(these versions have identical results)
0.10.48 v8 3.14.5.11
10% complete10% complete

features

Object static methods

§Object.values
?
function(){
var obj = Object.create({ a: "qux", d: "qux" }); obj.a = "foo"; obj.b = "bar"; obj.c = "baz"; var v = Object.values(obj); return Array.isArray(v) && String(v) === "foo,bar,baz";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§Object.entries
?
function(){
var obj = Object.create({ a: "qux", d: "qux" }); obj.a = "foo"; obj.b = "bar"; obj.c = "baz"; var e = Object.entries(obj); return Array.isArray(e) && e.length === 3 && String(e[0]) === "a,foo" && String(e[1]) === "b,bar" && String(e[2]) === "c,baz";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§Object.getOwnPropertyDescriptors
?
function(){
var object = {a: 1}; var B = typeof Symbol === 'function' ? Symbol('b') : 'b'; object[B] = 2; var O = Object.defineProperty(object, 'c', {value: 3}); var D = Object.getOwnPropertyDescriptors(O); return D.a.value === 1 && D.a.enumerable === true && D.a.configurable === true && D.a.writable === true && D[B].value === 2 && D[B].enumerable === true && D[B].configurable === true && D[B].writable === true && D.c.value === 3 && D.c.enumerable === false && D.c.configurable === false && D.c.writable === false;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§Object.getOwnPropertyDescriptors doesn't provide undefined descriptors
?
function(){
var P = new Proxy({a:1}, { getOwnPropertyDescriptor: function(t, k) {} }); return !Object.getOwnPropertyDescriptors(P).hasOwnProperty('a');
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error

String padding

§String.prototype.padStart
?
function(){
return 'hello'.padStart(10) === ' hello' && 'hello'.padStart(10, '1234') === '12341hello' && 'hello'.padStart() === 'hello' && 'hello'.padStart(6, '123') === '1hello' && 'hello'.padStart(3) === 'hello' && 'hello'.padStart(3, '123') === 'hello';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§String.prototype.padEnd
?
function(){
return 'hello'.padEnd(10) === 'hello ' && 'hello'.padEnd(10, '1234') === 'hello12341' && 'hello'.padEnd() === 'hello' && 'hello'.padEnd(6, '123') === 'hello1' && 'hello'.padEnd(3) === 'hello' && 'hello'.padEnd(3, '123') === 'hello';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error

trailing commas in function syntax

§in parameter lists
?
function(){
return typeof function f( a, b, ){} === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§in argument lists
?
function(){
return Math.min(1,2,3,) === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error

async functions

§return
?
function(){
async function a(){ return "foo"; } var p = a(); if (!(p instanceof Promise)) { return false; } p.then(function(result) { if (result === "foo") { asyncTestPassed(); } });
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§throw
?
function(){
async function a(){ throw "foo"; } var p = a(); if (!(p instanceof Promise)) { return false; } p.catch(function(result) { if (result === "foo") { asyncTestPassed(); } });
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§no line break between async and function
?
function(){
async function a(){} try { Function("async\n function a(){}")(); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§no "prototype" property
?
function(){
async function a(){}; return !a.hasOwnProperty("prototype");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§await
?
function(){
(async function (){ await Promise.resolve(); var a1 = await new Promise(function(resolve) { setTimeout(resolve,800,"foo"); }); var a2 = await new Promise(function(resolve) { setTimeout(resolve,800,"bar"); }); if (a1 + a2 === "foobar") { asyncTestPassed(); } }());
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§await, rejection
?
function(){
(async function (){ await Promise.resolve(); try { var a1 = await new Promise(function(_, reject) { setTimeout(reject,800,"foo"); }); } catch(e) { if (e === "foo") { asyncTestPassed(); } } }());
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§must await a value
?
function(){
async function a(){ await Promise.resolve(); } try { Function("(async function a(){ await; }())")(); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§can await non-Promise values
?
function(){
(async function (){ await Promise.resolve(); var e = await "foo"; if (e === "foo") { asyncTestPassed(); } }());
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§cannot await in parameters
?
function(){
async function a(){ await Promise.resolve(); } try { Function("(async function a(b = await Promise.resolve()){}())")(); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§async methods, object literals
?
function(){
var o = { async a(){ return await Promise.resolve("foo"); } }; var p = o.a(); if (!(p instanceof Promise)) { return false; } p.then(function(result) { if (result === "foo") { asyncTestPassed(); } });
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§async methods, classes
?
function(){
class C { async a(){ return await Promise.resolve("foo"); } }; var p = new C().a(); if (!(p instanceof Promise)) { return false; } p.then(function(result) { if (result === "foo") { asyncTestPassed(); } });
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§async arrow functions in methods, classes
?
function(){
function doSomething(callback) { callback(); } class C { a(){ doSomething(async () => { await 1; asyncTestPassed(); }); } }; var p = new C().a();
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No
§async arrow functions
?
function(){
var a = async () => await Promise.resolve("foo"); var p = a(); if (!(p instanceof Promise)) { return false; } p.then(function(result) { if (result === "foo") { asyncTestPassed(); } });
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§correct prototype chain
?
function(){
var asyncFunctionProto = Object.getPrototypeOf(async function (){}); return asyncFunctionProto !== function(){}.prototype && Object.getPrototypeOf(asyncFunctionProto) === Function.prototype;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§async function prototype, Symbol.toStringTag
?
function(){
return Object.getPrototypeOf(async function (){})[Symbol.toStringTag] == "AsyncFunction";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§async function constructor
?
function(){
var a = async function (){}.constructor("return 'foo';"); var p = a(); if (!(p instanceof Promise)) { return false; } p.then(function(result) { if (result === "foo") { asyncTestPassed(); } });
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error

shared memory and atomics

§SharedArrayBuffer
?
function(){
return typeof SharedArrayBuffer === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
§SharedArrayBuffer[Symbol.species]
?
function(){
return SharedArrayBuffer[Symbol.species] === SharedArrayBuffer;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§SharedArrayBuffer.prototype.byteLength
?
function(){
return 'byteLength' in SharedArrayBuffer.prototype;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§SharedArrayBuffer.prototype.slice
?
function(){
return typeof SharedArrayBuffer.prototype.slice === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§SharedArrayBuffer.prototype[Symbol.toStringTag]
?
function(){
return SharedArrayBuffer.prototype[Symbol.toStringTag] === 'SharedArrayBuffer';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§Atomics.add
?
function(){
return typeof Atomics.add == 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§Atomics.and
?
function(){
return typeof Atomics.and == 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§Atomics.compareExchange
?
function(){
return typeof Atomics.compareExchange == 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§Atomics.exchange
?
function(){
return typeof Atomics.exchange == 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§Atomics.wait
?
function(){
return typeof Atomics.wait == 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§Atomics.wake
?
function(){
return typeof Atomics.wake == 'function';
}
No
No
No
No
Yes
Yes
Yes
Yes
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§Atomics.isLockFree
?
function(){
return typeof Atomics.isLockFree == 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§Atomics.load
?
function(){
return typeof Atomics.load == 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§Atomics.or
?
function(){
return typeof Atomics.or == 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§Atomics.store
?
function(){
return typeof Atomics.store == 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§Atomics.sub
?
function(){
return typeof Atomics.sub == 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§Atomics.xor
?
function(){
return typeof Atomics.xor == 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error

misc

§Proxy "ownKeys" handler, duplicate keys for non-extensible targets (ES 2017 semantics)
?
function(){
var P = new Proxy(Object.preventExtensions(Object.defineProperty({a:1}, "b", {value:1})), { ownKeys: function() { return ['a','a','b','b']; } }); return Object.getOwnPropertyNames(P) + '' === "a,a,b,b";
}
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
§RegExp "u" flag, case folding
?
function(){
return "ſ".match(/\w/iu) && !"ſ".match(/\W/iu) && "\u212a".match(/\w/iu) && !"\u212a".match(/\W/iu) && "\u212a".match(/.\b/iu) && "ſ".match(/.\b/iu) && !"\u212a".match(/.\B/iu) && !"ſ".match(/.\B/iu);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
Error
Error
Error
Error
Error
Error
Error
Error
§arguments.caller removed
?
function(){
return (function(){ 'use strict'; return !Object.getOwnPropertyDescriptor(arguments,'caller'); })();
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No

annex b

Object.prototype getter/setter methods

§__defineGetter__
?
function(){
var obj = {}; function bar() { return "bar"; } Object.prototype.__defineGetter__.call(obj, "foo", bar); var prop = Object.getOwnPropertyDescriptor(obj, "foo"); return prop.get === bar && !prop.writable && prop.configurable && prop.enumerable;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§__defineGetter__, symbols
?
function(){
var obj = {}; var sym = Symbol(); function bar() { return "bar"; } Object.prototype.__defineGetter__.call(obj, sym, bar); var prop = Object.getOwnPropertyDescriptor(obj, sym); return prop.get === bar && !prop.writable && prop.configurable && prop.enumerable;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§__defineGetter__, ToObject(this)
?
function(){
var key = '__accessors_test__'; __defineGetter__.call(1, key, function(){}); try { __defineGetter__.call(null, key, function(){}); } catch(e){ return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
Flag
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
§__defineSetter__
?
function(){
var obj = {}; function bar() {} Object.prototype.__defineSetter__.call(obj, "foo", bar); var prop = Object.getOwnPropertyDescriptor(obj, "foo"); return prop.set === bar && !prop.writable && prop.configurable && prop.enumerable;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§__defineSetter__, symbols
?
function(){
var obj = {}; var sym = Symbol(); function bar(baz) {} Object.prototype.__defineSetter__.call(obj, sym, bar); var prop = Object.getOwnPropertyDescriptor(obj, sym); return prop.set === bar && !prop.writable && prop.configurable && prop.enumerable;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§__defineSetter__, ToObject(this)
?
function(){
var key = '__accessors_test__'; __defineSetter__.call(1, key, function(){}); try { __defineSetter__.call(null, key, function(){}); } catch(e){ return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
Flag
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
§__lookupGetter__
?
function(){
var obj = { get foo() { return "bar"}, qux: 1 }; var foo = Object.prototype.__lookupGetter__.call(obj, "foo"); return foo() === "bar" && Object.prototype.__lookupGetter__.call(obj, "qux") === undefined && Object.prototype.__lookupGetter__.call(obj, "baz") === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§__lookupGetter__, prototype chain
?
function(){
var obj = { get foo() { return "bar"}, qux: 1 }; var foo = Object.prototype.__lookupGetter__.call(Object.create(obj), "foo"); return foo() === "bar" && Object.prototype.__lookupGetter__.call(obj, "qux") === undefined && Object.prototype.__lookupGetter__.call(obj, "baz") === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§__lookupGetter__, symbols
?
function(){
var sym = Symbol(); var sym2 = Symbol(); var obj = {}; Object.defineProperty(obj, sym, { get: function() { return "bar"; }}); Object.defineProperty(obj, sym2, { value: 1 }); var foo = Object.prototype.__lookupGetter__.call(obj, sym); return foo() === "bar" && Object.prototype.__lookupGetter__.call(obj, sym2) === undefined && Object.prototype.__lookupGetter__.call(obj, Symbol()) === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§__lookupGetter__, ToObject(this)
?
function(){
__lookupGetter__.call(1, 'key'); try { __lookupGetter__.call(null, 'key'); } catch(e){ return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
Flag
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
§__lookupGetter__, data properties can shadow accessors
?
function(){
var a = { }; var b = Object.create(a); b.foo = 1; a.__defineGetter__("foo", function () {}) return b.__lookupGetter__("foo") === undefined
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
§__lookupSetter__
?
function(){
var obj = { set foo(baz) { return "bar"; }, qux: 1 }; var foo = Object.prototype.__lookupSetter__.call(obj, "foo"); return foo() === "bar" && Object.prototype.__lookupSetter__.call(obj, "qux") === undefined && Object.prototype.__lookupSetter__.call(obj, "baz") === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§__lookupSetter__, prototype chain
?
function(){
var obj = { set foo(baz) { return "bar"; }, qux: 1 }; var foo = Object.prototype.__lookupSetter__.call(Object.create(obj), "foo"); return foo() === "bar" && Object.prototype.__lookupSetter__.call(obj, "qux") === undefined && Object.prototype.__lookupSetter__.call(obj, "baz") === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
§__lookupSetter__, symbols
?
function(){
var sym = Symbol(); var sym2 = Symbol(); var obj = {}; Object.defineProperty(obj, sym, { set: function(baz) { return "bar"; }}); Object.defineProperty(obj, sym2, { value: 1 }); var foo = Object.prototype.__lookupSetter__.call(obj, sym); return foo() === "bar" && Object.prototype.__lookupSetter__.call(obj, sym2) === undefined && Object.prototype.__lookupSetter__.call(obj, Symbol()) === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
§__lookupSetter__, ToObject(this)
?
function(){
__lookupSetter__.call(1, 'key'); try { __lookupSetter__.call(null, 'key'); } catch(e){ return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
Flag
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
§__lookupSetter__, data properties can shadow accessors
?
function(){
var a = { }; var b = Object.create(a); b.foo = 1; a.__defineSetter__("foo", function () {}) return b.__lookupSetter__("foo") === undefined
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No

Proxy internal calls, getter/setter methods

§__defineGetter__
?
function(){
// Object.prototype.__defineGetter__ -> DefinePropertyOrThrow -> [[DefineOwnProperty]] var def = []; var p = new Proxy({}, { defineProperty: function(o, v, desc) { def.push(v); Object.defineProperty(o, v, desc); return true; }}); Object.prototype.__defineGetter__.call(p, "foo", Object); return def + '' === "foo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§__defineSetter__
?
function(){
// Object.prototype.__defineSetter__ -> DefinePropertyOrThrow -> [[DefineOwnProperty]] var def = []; var p = new Proxy({}, { defineProperty: function(o, v, desc) { def.push(v); Object.defineProperty(o, v, desc); return true; }}); Object.prototype.__defineSetter__.call(p, "foo", Object); return def + '' === "foo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
§__lookupGetter__
?
function(){
// Object.prototype.__lookupGetter__ -> [[GetOwnProperty]] // Object.prototype.__lookupGetter__ -> [[GetPrototypeOf]] var gopd = []; var gpo = false; var p = new Proxy({}, { getPrototypeOf: function(o) { gpo = true; return Object.getPrototypeOf(o); }, getOwnPropertyDescriptor: function(o, v) { gopd.push(v); return Object.getOwnPropertyDescriptor(o, v); } }); Object.prototype.__lookupGetter__.call(p, "foo"); return gopd + '' === "foo" && gpo;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
Error
Error
Error
Error
Error
Error
Error
Error
§__lookupSetter__
?
function(){
// Object.prototype.__lookupSetter__ -> [[GetOwnProperty]] // Object.prototype.__lookupSetter__ -> [[GetPrototypeOf]] var gopd = []; var gpo = false; var p = new Proxy({}, { getPrototypeOf: function(o) { gpo = true; return Object.getPrototypeOf(o); }, getOwnPropertyDescriptor: function(o, v) { gopd.push(v); return Object.getOwnPropertyDescriptor(o, v); } }); Object.prototype.__lookupSetter__.call(p, "foo"); return gopd + '' === "foo" && gpo;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
Error
Error
Error
Error
Error
Error
Error
Error

§assignments allowed in for-in head in non-strict mode
?
function(){
for (var i = 0 in {}) {} return i === 0;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes

Node.js ES2018 Support

14.0.0
(these versions have identical results)
nightly v8 7.8.279.17-node.19
Nightly!100% complete100% complete 		13.0.1
(these versions have identical results)
13.0.1 v8 7.8.279.17-node.14
13.0.0 v8 7.8.279.17-node.14
12.13.0 v8 7.7.299.13-node.12
12.12.0 v8 7.7.299.13-node.12
12.11.1 v8 7.7.299.11-node.12
12.11.0 v8 7.7.299.11-node.12
100% complete100% complete 		12.10.0
(these versions have identical results)
12.10.0 v8 7.6.303.29-node.16
12.9.1 v8 7.6.303.29-node.15
12.9.0 v8 7.6.303.29-node.15
100% complete100% complete 		12.8.1
(these versions have identical results)
12.8.1 v8 7.5.288.22-node.16
12.8.0 v8 7.5.288.22-node.16
12.7.0 v8 7.5.288.22-node.16
12.6.0 v8 7.5.288.22-node.14
12.5.0 v8 7.5.288.22-node.14
100% complete100% complete 		12.4.0
(these versions have identical results)
12.4.0 v8 7.4.288.27-node.18
12.3.1 v8 7.4.288.27-node.18
12.3.0 v8 7.4.288.27-node.17
12.2.0 v8 7.4.288.21-node.17
12.1.0 v8 7.4.288.21-node.16
12.0.0 v8 7.4.288.21-node.16
100% complete100% complete 		11.15.0
(these versions have identical results)
11.15.0 v8 7.0.276.38-node.19
11.14.0 v8 7.0.276.38-node.18
11.13.0 v8 7.0.276.38-node.18
11.12.0 v8 7.0.276.38-node.18
11.11.0 v8 7.0.276.38-node.18
11.10.1 v8 7.0.276.38-node.17
11.10.0 v8 7.0.276.38-node.17
11.9.0 v8 7.0.276.38-node.16
11.8.0 v8 7.0.276.38-node.16
11.7.0 v8 7.0.276.38-node.16
11.6.0 v8 7.0.276.38-node.13
11.5.0 v8 7.0.276.38-node.13
11.4.0 v8 7.0.276.38-node.13
11.3.0 v8 7.0.276.38-node.11
11.2.0 v8 7.0.276.38-node.11
11.1.0 v8 7.0.276.32-node.7
11.0.0 v8 7.0.276.28-node.5
100% complete100% complete 		10.17.0
(these versions have identical results)
10.17.0 v8 6.8.275.32-node.54
10.16.3 v8 6.8.275.32-node.54
10.16.2 v8 6.8.275.32-node.54
10.16.1 v8 6.8.275.32-node.54
10.16.0 v8 6.8.275.32-node.52
10.15.3 v8 6.8.275.32-node.51
10.15.2 v8 6.8.275.32-node.12
10.15.1 v8 6.8.275.32-node.12
10.15.0 v8 6.8.275.32-node.45
10.14.2 v8 6.8.275.32-node.45
10.14.1 v8 6.8.275.32-node.36
10.14.0 v8 6.8.275.32-node.36
10.13.0 v8 6.8.275.32-node.36
10.12.0 v8 6.8.275.32-node.35
10.11.0 v8 6.8.275.32-node.28
10.10.0 v8 6.8.275.30-node.24
10.9.0 v8 6.8.275.24-node.14
100% complete100% complete 		10.8.0
(these versions have identical results)
10.8.0 v8 6.7.288.49-node.19
10.7.0 v8 6.7.288.49-node.15
10.6.0 v8 6.7.288.46-node.13
10.5.0 v8 6.7.288.46-node.8
10.4.1 v8 6.7.288.45-node.7
10.4.0 v8 6.7.288.43-node.7
100% complete100% complete 		10.3.0
(these versions have identical results)
10.3.0 v8 6.6.346.32-node.9
10.2.1 v8 6.6.346.32-node.8
10.2.0 v8 6.6.346.32-node.8
10.1.0 v8 6.6.346.27-node.6
10.0.0 v8 6.6.346.24-node.5
100% complete100% complete 		9.11.2
(these versions have identical results)
9.11.2 v8 6.2.414.46-node.23
9.11.1 v8 6.2.414.46-node.23
9.11.0 v8 6.2.414.46-node.23
9.10.1 v8 6.2.414.46-node.23
9.10.0 v8 6.2.414.46-node.23
9.9.0 v8 6.2.414.46-node.22
9.8.0 v8 6.2.414.46-node.21
9.7.1 v8 6.2.414.46-node.20
9.7.0 v8 6.2.414.46-node.20
9.6.1 v8 6.2.414.46-node.20
9.6.0 v8 6.2.414.46-node.20
9.5.0 v8 6.2.414.46-node.18
9.4.0 v8 6.2.414.46-node.17
9.3.0 v8 6.2.414.46-node.15
9.2.1 v8 6.2.414.44-node.11
9.2.0 v8 6.2.414.44-node.11
9.1.0 v8 6.2.414.32-node.8
9.0.0 v8 6.2.414.32-node.8
8.16.2 v8 6.2.414.78
8.16.1 v8 6.2.414.77
8.16.0 v8 6.2.414.77
8.15.1 v8 6.2.414.75
8.15.0 v8 6.2.414.75
8.14.1 v8 6.2.414.75
8.14.0 v8 6.2.414.72
8.13.0 v8 6.2.414.72
8.12.0 v8 6.2.414.66
8.11.4 v8 6.2.414.54
8.11.3 v8 6.2.414.54
8.11.2 v8 6.2.414.54
8.11.1 v8 6.2.414.50
8.11.0 v8 6.2.414.50
8.10.0 v8 6.2.414.50
75% complete41% complete 		8.9.4
(these versions have identical results)
8.9.4 v8 6.1.534.50
8.9.3 v8 6.1.534.48
8.9.2 v8 6.1.534.48
8.9.1 v8 6.1.534.47
8.9.0 v8 6.1.534.46
8.8.1 v8 6.1.534.42
8.8.0 v8 6.1.534.42
8.7.0 v8 6.1.534.42
58% complete16% complete 		8.6.0
(these versions have identical results)
8.6.0 v8 6.0.287.53
8.5.0 v8 6.0.287.53
8.4.0 v8 6.0.286.52
8.3.0 v8 6.0.286.52
58% complete16% complete 		8.2.1
(these versions have identical results)
8.2.1 v8 5.8.283.41
8.2.0 v8 5.8.283.41
8.1.4 v8 5.8.283.41
8.1.3 v8 5.8.283.41
8.1.2 v8 5.8.283.41
8.1.1 v8 5.8.283.41
8.1.0 v8 5.8.283.41
8.0.0 v8 5.8.283.41
33% complete0% complete 		7.10.1
(these versions have identical results)
7.10.1 v8 5.5.372.43
7.10.0 v8 5.5.372.43
7.9.0 v8 5.5.372.43
7.8.0 v8 5.5.372.43
7.7.4 v8 5.5.372.42
7.7.3 v8 5.5.372.41
7.7.2 v8 5.5.372.41
7.7.1 v8 5.5.372.41
7.7.0 v8 5.5.372.41
7.6.0 v8 5.5.372.40
8% complete0% complete 		7.5.0
(these versions have identical results)
7.5.0 v8 5.4.500.48
7.4.0 v8 5.4.500.45
7.3.0 v8 5.4.500.45
7.2.1 v8 5.4.500.44
7.2.0 v8 5.4.500.43
7.1.0 v8 5.4.500.36
7.0.0 v8 5.4.500.36
8% complete0% complete 		6.17.1
(these versions have identical results)
6.17.1 v8 5.1.281.111
6.17.0 v8 5.1.281.111
6.16.0 v8 5.1.281.111
6.15.1 v8 5.1.281.111
6.15.0 v8 5.1.281.111
6.14.4 v8 5.1.281.111
6.14.3 v8 5.1.281.111
6.14.2 v8 5.1.281.111
6.14.1 v8 5.1.281.111
6.14.0 v8 5.1.281.111
6.13.1 v8 5.1.281.111
6.13.0 v8 5.1.281.111
6.12.3 v8 5.1.281.111
6.12.2 v8 5.1.281.109
6.12.1 v8 5.1.281.109
6.12.0 v8 5.1.281.108
6.11.5 v8 5.1.281.108
6.11.4 v8 5.1.281.108
6.11.3 v8 5.1.281.107
6.11.2 v8 5.1.281.103
6.11.1 v8 5.1.281.103
6.11.0 v8 5.1.281.102
6.10.3 v8 5.1.281.101
6.10.2 v8 5.1.281.98
6.10.1 v8 5.1.281.95
6.10.0 v8 5.1.281.93
6.9.5 v8 5.1.281.89
6.9.4 v8 5.1.281.89
6.9.3 v8 5.1.281.89
6.9.2 v8 5.1.281.88
6.9.1 v8 5.1.281.84
6.9.0 v8 5.1.281.84
6.8.1 v8 5.1.281.84
6.8.0 v8 5.1.281.84
6.7.0 v8 5.1.281.83
6.6.0 v8 5.1.281.83
6.5.0 v8 5.1.281.81
8% complete0% complete 		6.4.0
(these versions have identical results)
6.4.0 v8 5.0.71.60
6.3.1 v8 5.0.71.57
6.3.0 v8 5.0.71.52
6.2.2 v8 5.0.71.52
6.2.1 v8 5.0.71.52
6.2.0 v8 5.0.71.47
6.1.0 v8 5.0.71.35
6.0.0 v8 5.0.71.35
8% complete0% complete 		5.12.0
(these versions have identical results)
5.12.0 v8 4.6.85.32
5.11.1 v8 4.6.85.31
5.11.0 v8 4.6.85.31
5.10.1 v8 4.6.85.31
5.10.0 v8 4.6.85.31
5.9.1 v8 4.6.85.31
5.9.0 v8 4.6.85.31
5.8.0 v8 4.6.85.31
5.7.1 v8 4.6.85.31
5.7.0 v8 4.6.85.31
5.6.0 v8 4.6.85.31
5.5.0 v8 4.6.85.31
5.4.1 v8 4.6.85.31
5.4.0 v8 4.6.85.31
5.3.0 v8 4.6.85.31
5.2.0 v8 4.6.85.31
5.1.1 v8 4.6.85.31
5.1.0 v8 4.6.85.31
5.0.0 v8 4.6.85.28
0% complete0% complete 		4.9.1
(these versions have identical results)
4.9.1 v8 4.5.103.53
4.9.0 v8 4.5.103.53
4.8.7 v8 4.5.103.53
4.8.6 v8 4.5.103.53
4.8.5 v8 4.5.103.47
4.8.4 v8 4.5.103.47
4.8.3 v8 4.5.103.47
4.8.2 v8 4.5.103.46
4.8.1 v8 4.5.103.46
4.8.0 v8 4.5.103.45
4.7.3 v8 4.5.103.43
4.7.2 v8 4.5.103.43
4.7.1 v8 4.5.103.43
4.7.0 v8 4.5.103.43
4.6.2 v8 4.5.103.42
4.6.1 v8 4.5.103.37
4.6.0 v8 4.5.103.37
4.5.0 v8 4.5.103.37
4.4.7 v8 4.5.103.36
4.4.6 v8 4.5.103.36
4.4.5 v8 4.5.103.35
4.4.4 v8 4.5.103.35
4.4.3 v8 4.5.103.35
4.4.2 v8 4.5.103.35
4.4.1 v8 4.5.103.35
4.4.0 v8 4.5.103.35
4.3.2 v8 4.5.103.35
4.3.1 v8 4.5.103.35
4.3.0 v8 4.5.103.35
4.2.6 v8 4.5.103.35
4.2.5 v8 4.5.103.35
4.2.4 v8 4.5.103.35
4.2.3 v8 4.5.103.35
4.2.2 v8 4.5.103.35
4.2.1 v8 4.5.103.35
4.2.0 v8 4.5.103.35
4.1.2 v8 4.5.103.35
4.1.1 v8 4.5.103.33
4.1.0 v8 4.5.103.33
4.0.0 v8 4.5.103.30
0% complete0% complete 		0.12.18
(these versions have identical results)
0.12.18 v8 3.28.71.20
0% complete0% complete 		0.10.48
(these versions have identical results)
0.10.48 v8 3.14.5.11
0% complete0% complete

features

object rest/spread properties

§object rest properties
?
function(){
var {a, ...rest} = {a: 1, b: 2, c: 3}; return a === 1 && rest.a === undefined && rest.b === 2 && rest.c === 3;
}
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§object spread properties
?
function(){
var spread = {b: 2, c: 3}; var O = {a: 1, ...spread}; return O !== spread && (O.a + O.b + O.c) === 6;
}
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Promise.prototype.finally

§basic support
?
function(){
var p1 = Promise.resolve("foo"); var p2 = Promise.reject("bar"); var score = 0; function thenFn(result) { score += (result === "foo"); check(); } function catchFn(result) { score += (result === "bar"); check(); } function finallyFn() { score += (arguments.length === 0); check(); } p1.then(thenFn); p1.finally(finallyFn); p1.finally(function() { // should return a new Promise score += p1.finally() !== p1; check(); }); p2.catch(catchFn); p2.finally(finallyFn); function check() { if (score === 5) asyncTestPassed(); }
}
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§don't change resolution value
?
function(){
var score = 0; function thenFn(result) { score += (result === "foo"); check(); } function catchFn(result) { score += (result === "bar"); check(); } function finallyFn() { score++; check(); return Promise.resolve("foobar"); } Promise.resolve("foo").finally(finallyFn).then(thenFn); Promise.reject("bar").finally(finallyFn).catch(catchFn); function check() { if (score === 4) asyncTestPassed(); }
}
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§change rejection value
?
function(){
var score = 0; Promise .reject("foobar") .finally(function() { return Promise.reject("foo"); }) .catch(function(result) { score += (result === "foo"); check(); return Promise.reject("foobar"); }) .finally(function() { throw new Error('bar'); }) .catch(function(result) { score += (result.message === "bar"); check(); }); function check() { if (score === 2) asyncTestPassed(); }
}
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§s (dotAll) flag for regular expressions
?
function(){
const regex = /foo.bar/s; return regex.test('foo\nbar');
}
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§RegExp named capture groups
?
function(){
var result = /(?<year>\d{4})-(?<month>\d{2})-(?<day>\d{2})/.exec('2016-03-11'); return result.groups.year === '2016' && result.groups.month === '03' && result.groups.day === '11' && result[0] === '2016-03-11' && result[1] === '2016' && result[2] === '03' && result[3] === '11';
}
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§RegExp Lookbehind Assertions
?
function(){
return /(?<=a)b/.test('ab') && /(?<!a)b/.test('cb') && !/(?<=a)b/.test('b');
}
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§RegExp Unicode Property Escapes
?
function(){
const regexGreekSymbol = /\p{Script=Greek}/u; return regexGreekSymbol.test('π');
}
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Asynchronous Iterators

§async generators
?
function(){
async function*generator(){ yield 42; } var iterator = generator(); iterator.next().then(function(step){ if(iterator[Symbol.asyncIterator]() === iterator && step.done === false && step.value === 42)asyncTestPassed(); });
}
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§for-await-of loops
?
function(){
var asyncIterable = {}; asyncIterable[Symbol.asyncIterator] = function(){ var i = 0; return { next: function(){ switch(++i){ case 1: return Promise.resolve({done: false, value: 'a'}); case 2: return Promise.resolve({done: false, value: 'b'}); } return Promise.resolve({done: true}); } }; }; (async function(){ var result = ''; for await(var value of asyncIterable)result += value; if(result === 'ab')asyncTestPassed(); })();
}
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misc

§template literal revision
?
function(){
function tag(strings, a) { return strings[0] === void 0 && strings.raw[0] === "\\01\\1\\xg\\xAg\\u0\\u0g\\u00g\\u000g\\u{g\\u{0\\u{110000}" && strings[1] === "\0" && strings.raw[1] === "\\0" && a === 0; } return tag`\01\1\xg\xAg\u0\u0g\u00g\u000g\u{g\u{0\u{110000}${0}\0`;
}
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No

Node.js ES2019 Support

14.0.0
(these versions have identical results)
nightly v8 7.8.279.17-node.19
Nightly!100% complete100% complete 		13.0.1
(these versions have identical results)
13.0.1 v8 7.8.279.17-node.14
13.0.0 v8 7.8.279.17-node.14
12.13.0 v8 7.7.299.13-node.12
12.12.0 v8 7.7.299.13-node.12
12.11.1 v8 7.7.299.11-node.12
12.11.0 v8 7.7.299.11-node.12
100% complete100% complete 		12.10.0
(these versions have identical results)
12.10.0 v8 7.6.303.29-node.16
12.9.1 v8 7.6.303.29-node.15
12.9.0 v8 7.6.303.29-node.15
100% complete100% complete 		12.8.1
(these versions have identical results)
12.8.1 v8 7.5.288.22-node.16
12.8.0 v8 7.5.288.22-node.16
12.7.0 v8 7.5.288.22-node.16
12.6.0 v8 7.5.288.22-node.14
12.5.0 v8 7.5.288.22-node.14
100% complete100% complete 		12.4.0
(these versions have identical results)
12.4.0 v8 7.4.288.27-node.18
12.3.1 v8 7.4.288.27-node.18
12.3.0 v8 7.4.288.27-node.17
12.2.0 v8 7.4.288.21-node.17
12.1.0 v8 7.4.288.21-node.16
12.0.0 v8 7.4.288.21-node.16
100% complete100% complete 		11.15.0
(these versions have identical results)
11.15.0 v8 7.0.276.38-node.19
11.14.0 v8 7.0.276.38-node.18
11.13.0 v8 7.0.276.38-node.18
11.12.0 v8 7.0.276.38-node.18
11.11.0 v8 7.0.276.38-node.18
11.10.1 v8 7.0.276.38-node.17
11.10.0 v8 7.0.276.38-node.17
11.9.0 v8 7.0.276.38-node.16
11.8.0 v8 7.0.276.38-node.16
11.7.0 v8 7.0.276.38-node.16
11.6.0 v8 7.0.276.38-node.13
11.5.0 v8 7.0.276.38-node.13
11.4.0 v8 7.0.276.38-node.13
11.3.0 v8 7.0.276.38-node.11
11.2.0 v8 7.0.276.38-node.11
11.1.0 v8 7.0.276.32-node.7
11.0.0 v8 7.0.276.28-node.5
87% complete87% complete 		10.17.0
(these versions have identical results)
10.17.0 v8 6.8.275.32-node.54
10.16.3 v8 6.8.275.32-node.54
10.16.2 v8 6.8.275.32-node.54
10.16.1 v8 6.8.275.32-node.54
10.16.0 v8 6.8.275.32-node.52
10.15.3 v8 6.8.275.32-node.51
10.15.2 v8 6.8.275.32-node.12
10.15.1 v8 6.8.275.32-node.12
10.15.0 v8 6.8.275.32-node.45
10.14.2 v8 6.8.275.32-node.45
10.14.1 v8 6.8.275.32-node.36
10.14.0 v8 6.8.275.32-node.36
10.13.0 v8 6.8.275.32-node.36
10.12.0 v8 6.8.275.32-node.35
10.11.0 v8 6.8.275.32-node.28
10.10.0 v8 6.8.275.30-node.24
10.9.0 v8 6.8.275.24-node.14
66% complete66% complete 		10.8.0
(these versions have identical results)
10.8.0 v8 6.7.288.49-node.19
10.7.0 v8 6.7.288.49-node.15
10.6.0 v8 6.7.288.46-node.13
10.5.0 v8 6.7.288.46-node.8
10.4.1 v8 6.7.288.45-node.7
10.4.0 v8 6.7.288.43-node.7
66% complete66% complete 		10.3.0
(these versions have identical results)
10.3.0 v8 6.6.346.32-node.9
10.2.1 v8 6.6.346.32-node.8
10.2.0 v8 6.6.346.32-node.8
10.1.0 v8 6.6.346.27-node.6
10.0.0 v8 6.6.346.24-node.5
66% complete66% complete 		9.11.2
(these versions have identical results)
9.11.2 v8 6.2.414.46-node.23
9.11.1 v8 6.2.414.46-node.23
9.11.0 v8 6.2.414.46-node.23
9.10.1 v8 6.2.414.46-node.23
9.10.0 v8 6.2.414.46-node.23
9.9.0 v8 6.2.414.46-node.22
9.8.0 v8 6.2.414.46-node.21
9.7.1 v8 6.2.414.46-node.20
9.7.0 v8 6.2.414.46-node.20
9.6.1 v8 6.2.414.46-node.20
9.6.0 v8 6.2.414.46-node.20
9.5.0 v8 6.2.414.46-node.18
9.4.0 v8 6.2.414.46-node.17
9.3.0 v8 6.2.414.46-node.15
9.2.1 v8 6.2.414.44-node.11
9.2.0 v8 6.2.414.44-node.11
9.1.0 v8 6.2.414.32-node.8
9.0.0 v8 6.2.414.32-node.8
8.16.2 v8 6.2.414.78
8.16.1 v8 6.2.414.77
8.16.0 v8 6.2.414.77
8.15.1 v8 6.2.414.75
8.15.0 v8 6.2.414.75
8.14.1 v8 6.2.414.75
8.14.0 v8 6.2.414.72
8.13.0 v8 6.2.414.72
8.12.0 v8 6.2.414.66
8.11.4 v8 6.2.414.54
8.11.3 v8 6.2.414.54
8.11.2 v8 6.2.414.54
8.11.1 v8 6.2.414.50
8.11.0 v8 6.2.414.50
8.10.0 v8 6.2.414.50
37% complete25% complete 		8.9.4
(these versions have identical results)
8.9.4 v8 6.1.534.50
8.9.3 v8 6.1.534.48
8.9.2 v8 6.1.534.48
8.9.1 v8 6.1.534.47
8.9.0 v8 6.1.534.46
8.8.1 v8 6.1.534.42
8.8.0 v8 6.1.534.42
8.7.0 v8 6.1.534.42
37% complete25% complete 		8.6.0
(these versions have identical results)
8.6.0 v8 6.0.287.53
8.5.0 v8 6.0.287.53
8.4.0 v8 6.0.286.52
8.3.0 v8 6.0.286.52
37% complete25% complete 		8.2.1
(these versions have identical results)
8.2.1 v8 5.8.283.41
8.2.0 v8 5.8.283.41
8.1.4 v8 5.8.283.41
8.1.3 v8 5.8.283.41
8.1.2 v8 5.8.283.41
8.1.1 v8 5.8.283.41
8.1.0 v8 5.8.283.41
8.0.0 v8 5.8.283.41
25% complete25% complete 		7.10.1
(these versions have identical results)
7.10.1 v8 5.5.372.43
7.10.0 v8 5.5.372.43
7.9.0 v8 5.5.372.43
7.8.0 v8 5.5.372.43
7.7.4 v8 5.5.372.42
7.7.3 v8 5.5.372.41
7.7.2 v8 5.5.372.41
7.7.1 v8 5.5.372.41
7.7.0 v8 5.5.372.41
7.6.0 v8 5.5.372.40
25% complete25% complete 		7.5.0
(these versions have identical results)
7.5.0 v8 5.4.500.48
7.4.0 v8 5.4.500.45
7.3.0 v8 5.4.500.45
7.2.1 v8 5.4.500.44
7.2.0 v8 5.4.500.43
7.1.0 v8 5.4.500.36
7.0.0 v8 5.4.500.36
25% complete25% complete 		6.17.1
(these versions have identical results)
6.17.1 v8 5.1.281.111
6.17.0 v8 5.1.281.111
6.16.0 v8 5.1.281.111
6.15.1 v8 5.1.281.111
6.15.0 v8 5.1.281.111
6.14.4 v8 5.1.281.111
6.14.3 v8 5.1.281.111
6.14.2 v8 5.1.281.111
6.14.1 v8 5.1.281.111
6.14.0 v8 5.1.281.111
6.13.1 v8 5.1.281.111
6.13.0 v8 5.1.281.111
6.12.3 v8 5.1.281.111
6.12.2 v8 5.1.281.109
6.12.1 v8 5.1.281.109
6.12.0 v8 5.1.281.108
6.11.5 v8 5.1.281.108
6.11.4 v8 5.1.281.108
6.11.3 v8 5.1.281.107
6.11.2 v8 5.1.281.103
6.11.1 v8 5.1.281.103
6.11.0 v8 5.1.281.102
6.10.3 v8 5.1.281.101
6.10.2 v8 5.1.281.98
6.10.1 v8 5.1.281.95
6.10.0 v8 5.1.281.93
6.9.5 v8 5.1.281.89
6.9.4 v8 5.1.281.89
6.9.3 v8 5.1.281.89
6.9.2 v8 5.1.281.88
6.9.1 v8 5.1.281.84
6.9.0 v8 5.1.281.84
6.8.1 v8 5.1.281.84
6.8.0 v8 5.1.281.84
6.7.0 v8 5.1.281.83
6.6.0 v8 5.1.281.83
6.5.0 v8 5.1.281.81
25% complete25% complete 		6.4.0
(these versions have identical results)
6.4.0 v8 5.0.71.60
6.3.1 v8 5.0.71.57
6.3.0 v8 5.0.71.52
6.2.2 v8 5.0.71.52
6.2.1 v8 5.0.71.52
6.2.0 v8 5.0.71.47
6.1.0 v8 5.0.71.35
6.0.0 v8 5.0.71.35
25% complete25% complete 		5.12.0
(these versions have identical results)
5.12.0 v8 4.6.85.32
5.11.1 v8 4.6.85.31
5.11.0 v8 4.6.85.31
5.10.1 v8 4.6.85.31
5.10.0 v8 4.6.85.31
5.9.1 v8 4.6.85.31
5.9.0 v8 4.6.85.31
5.8.0 v8 4.6.85.31
5.7.1 v8 4.6.85.31
5.7.0 v8 4.6.85.31
5.6.0 v8 4.6.85.31
5.5.0 v8 4.6.85.31
5.4.1 v8 4.6.85.31
5.4.0 v8 4.6.85.31
5.3.0 v8 4.6.85.31
5.2.0 v8 4.6.85.31
5.1.1 v8 4.6.85.31
5.1.0 v8 4.6.85.31
5.0.0 v8 4.6.85.28
25% complete16% complete 		4.9.1
(these versions have identical results)
4.9.1 v8 4.5.103.53
4.9.0 v8 4.5.103.53
4.8.7 v8 4.5.103.53
4.8.6 v8 4.5.103.53
4.8.5 v8 4.5.103.47
4.8.4 v8 4.5.103.47
4.8.3 v8 4.5.103.47
4.8.2 v8 4.5.103.46
4.8.1 v8 4.5.103.46
4.8.0 v8 4.5.103.45
4.7.3 v8 4.5.103.43
4.7.2 v8 4.5.103.43
4.7.1 v8 4.5.103.43
4.7.0 v8 4.5.103.43
4.6.2 v8 4.5.103.42
4.6.1 v8 4.5.103.37
4.6.0 v8 4.5.103.37
4.5.0 v8 4.5.103.37
4.4.7 v8 4.5.103.36
4.4.6 v8 4.5.103.36
4.4.5 v8 4.5.103.35
4.4.4 v8 4.5.103.35
4.4.3 v8 4.5.103.35
4.4.2 v8 4.5.103.35
4.4.1 v8 4.5.103.35
4.4.0 v8 4.5.103.35
4.3.2 v8 4.5.103.35
4.3.1 v8 4.5.103.35
4.3.0 v8 4.5.103.35
4.2.6 v8 4.5.103.35
4.2.5 v8 4.5.103.35
4.2.4 v8 4.5.103.35
4.2.3 v8 4.5.103.35
4.2.2 v8 4.5.103.35
4.2.1 v8 4.5.103.35
4.2.0 v8 4.5.103.35
4.1.2 v8 4.5.103.35
4.1.1 v8 4.5.103.33
4.1.0 v8 4.5.103.33
4.0.0 v8 4.5.103.30
16% complete16% complete 		0.12.18
(these versions have identical results)
0.12.18 v8 3.28.71.20
16% complete% complete 		0.10.48
(these versions have identical results)
0.10.48 v8 3.14.5.11
% complete% complete

features

§Object.fromEntries
?
function(){
var object = Object.fromEntries(new Map([['foo', 42], ['bar', 23]])); return object.foo === 42 && object.bar === 23;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No

string trimming

§String.prototype.trimLeft
?
function(){
return ' \t \n abc \t\n'.trimLeft() === 'abc \t\n';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
No
No
§String.prototype.trimRight
?
function(){
return ' \t \n abc \t\n'.trimRight() === ' \t \n abc';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
No
No
§String.prototype.trimStart
?
function(){
return ' \t \n abc \t\n'.trimStart() === 'abc \t\n';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No
§String.prototype.trimEnd
?
function(){
return ' \t \n abc \t\n'.trimEnd() === ' \t \n abc';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No

Array.prototype.{flat, flatMap}

§Array.prototype.flat
?
function(){
return [1, [2, 3], [4, [5, 6]]].flat().join('') === '12345,6';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No
§Array.prototype.flatMap
?
function(){
return [{a: 1, b: 2}, {a: 3, b: 4}].flatMap(function (it) { return [it.a, it.b]; }).join('') === '1234';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No
§flat and flatMap in Array.prototype[@@unscopables]
?
function(){
return Array.prototype[Symbol.unscopables].flat && Array.prototype[Symbol.unscopables].flatMap;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No

misc

optional catch binding

§basic
?
function(){
try { throw new Error(); } catch { return true; } return false;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No
§await
?
function(){
(async function (){ try { await Promise.reject(); } catch { asyncTestPassed(); } })();
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No
§yield
?
function(){
function *foo() { try { yield; throw new Error(); } catch { return true; } } var it = foo(); it.next(); return it.next().value;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No

Symbol.prototype.description

§basic
?
function(){
return Symbol('foo').description === 'foo';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
§empty description
?
function(){
return Symbol('').description === '';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
§undefined description
?
function(){
return Symbol.prototype.hasOwnProperty('description') && Symbol().description === undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No

Function.prototype.toString revision

§functions created with the Function constructor
?
function(){
var fn = Function('a', ' /\x2A a \x2A/ b, c /\x2A b \x2A/ //', '/\x2A c \x2A/ ; /\x2A d \x2A/ //'); var str = 'function anonymous(a, /\x2A a \x2A/ b, c /\x2A b \x2A/ //\n) {\n/\x2A c \x2A/ ; /\x2A d \x2A/ //\n}'; return fn + '' === str;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
Flag
No
Flag
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
§arrows
?
function(){
var str = 'a => b'; return eval('(' + str + ')') + '' === str;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
No
No
§[native code]
?
function(){
const NATIVE_EVAL_RE = /\bfunction\b[\s\S]*\beval\b[\s\S]*\([\s\S]*\)[\s\S]*\{[\s\S]*\[[\s\S]*\bnative\b[\s\S]+\bcode\b[\s\S]*\][\s\S]*\}/; return NATIVE_EVAL_RE.test(eval + '');
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
No
No
§class expression with implicit constructor
?
function(){
var str = 'class A {}'; return eval('(' + str + ')') + '' === str;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
No
Error
No
No
§class expression with explicit constructor
?
function(){
var str = 'class /\x2A a \x2A/ A /\x2A b \x2A/ extends /\x2A c \x2A/ function B(){} /\x2A d \x2A/ { /\x2A e \x2A/ constructor /\x2A f \x2A/ ( /\x2A g \x2A/ ) /\x2A h \x2A/ { /\x2A i \x2A/ ; /\x2A j \x2A/ } /\x2A k \x2A/ m /\x2A l \x2A/ ( /\x2A m \x2A/ ) /\x2A n \x2A/ { /\x2A o \x2A/ } /\x2A p \x2A/ }'; return eval('(/\x2A before \x2A/' + str + '/\x2A after \x2A/)') + '' === str;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
No
Error
No
No
§unicode escape sequences in identifiers
?
function(){
var str = 'function \\u0061(\\u{62}, \\u0063) { \\u0062 = \\u{00063}; return b; }'; return eval('(/\x2A before \x2A/' + str + '/\x2A after \x2A/)') + '' === str;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
Flag
No
Flag
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Error
No
No
§methods and computed property names
?
function(){
var str = '[ /\x2A a \x2A/ "f" /\x2A b \x2A/ ] /\x2A c \x2A/ ( /\x2A d \x2A/ ) /\x2A e \x2A/ { /\x2A f \x2A/ }'; return eval('({ /\x2A before \x2A/' + str + '/\x2A after \x2A/ }.f)') + '' === str;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
Flag
No
Flag
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Error
No
No

JSON superset

§LINE SEPARATOR can appear in string literals
?
function(){
return eval("'\u2028'") === "\u2028";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No
§PARAGRAPH SEPARATOR can appear in string literals
?
function(){
return eval("'\u2029'") === "\u2029";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No

§Well-formed JSON.stringify
?
function(){
return JSON.stringify('\uDF06\uD834') === "\"\\udf06\\ud834\"" && JSON.stringify('\uDEAD') === "\"\\udead\"";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No

Node.js ES2020 Support

14.0.0
(these versions have identical results)
nightly v8 7.8.279.17-node.19
Nightly!92% complete92% complete 		13.0.1
(these versions have identical results)
13.0.1 v8 7.8.279.17-node.14
13.0.0 v8 7.8.279.17-node.14
12.13.0 v8 7.7.299.13-node.12
12.12.0 v8 7.7.299.13-node.12
12.11.1 v8 7.7.299.11-node.12
12.11.0 v8 7.7.299.11-node.12
92% complete92% complete 		12.10.0
(these versions have identical results)
12.10.0 v8 7.6.303.29-node.16
12.9.1 v8 7.6.303.29-node.15
12.9.0 v8 7.6.303.29-node.15
92% complete92% complete 		12.8.1
(these versions have identical results)
12.8.1 v8 7.5.288.22-node.16
12.8.0 v8 7.5.288.22-node.16
12.7.0 v8 7.5.288.22-node.16
12.6.0 v8 7.5.288.22-node.14
12.5.0 v8 7.5.288.22-node.14
92% complete84% complete 		12.4.0
(these versions have identical results)
12.4.0 v8 7.4.288.27-node.18
12.3.1 v8 7.4.288.27-node.18
12.3.0 v8 7.4.288.27-node.17
12.2.0 v8 7.4.288.21-node.17
12.1.0 v8 7.4.288.21-node.16
12.0.0 v8 7.4.288.21-node.16
84% complete84% complete 		11.15.0
(these versions have identical results)
11.15.0 v8 7.0.276.38-node.19
11.14.0 v8 7.0.276.38-node.18
11.13.0 v8 7.0.276.38-node.18
11.12.0 v8 7.0.276.38-node.18
11.11.0 v8 7.0.276.38-node.18
11.10.1 v8 7.0.276.38-node.17
11.10.0 v8 7.0.276.38-node.17
11.9.0 v8 7.0.276.38-node.16
11.8.0 v8 7.0.276.38-node.16
11.7.0 v8 7.0.276.38-node.16
11.6.0 v8 7.0.276.38-node.13
11.5.0 v8 7.0.276.38-node.13
11.4.0 v8 7.0.276.38-node.13
11.3.0 v8 7.0.276.38-node.11
11.2.0 v8 7.0.276.38-node.11
11.1.0 v8 7.0.276.32-node.7
11.0.0 v8 7.0.276.28-node.5
84% complete61% complete 		10.17.0
(these versions have identical results)
10.17.0 v8 6.8.275.32-node.54
10.16.3 v8 6.8.275.32-node.54
10.16.2 v8 6.8.275.32-node.54
10.16.1 v8 6.8.275.32-node.54
10.16.0 v8 6.8.275.32-node.52
10.15.3 v8 6.8.275.32-node.51
10.15.2 v8 6.8.275.32-node.12
10.15.1 v8 6.8.275.32-node.12
10.15.0 v8 6.8.275.32-node.45
10.14.2 v8 6.8.275.32-node.45
10.14.1 v8 6.8.275.32-node.36
10.14.0 v8 6.8.275.32-node.36
10.13.0 v8 6.8.275.32-node.36
10.12.0 v8 6.8.275.32-node.35
10.11.0 v8 6.8.275.32-node.28
10.10.0 v8 6.8.275.30-node.24
10.9.0 v8 6.8.275.24-node.14
69% complete61% complete 		10.8.0
(these versions have identical results)
10.8.0 v8 6.7.288.49-node.19
10.7.0 v8 6.7.288.49-node.15
10.6.0 v8 6.7.288.46-node.13
10.5.0 v8 6.7.288.46-node.8
10.4.1 v8 6.7.288.45-node.7
10.4.0 v8 6.7.288.43-node.7
61% complete61% complete 		10.3.0
(these versions have identical results)
10.3.0 v8 6.6.346.32-node.9
10.2.1 v8 6.6.346.32-node.8
10.2.0 v8 6.6.346.32-node.8
10.1.0 v8 6.6.346.27-node.6
10.0.0 v8 6.6.346.24-node.5
0% complete0% complete 		9.11.2
(these versions have identical results)
9.11.2 v8 6.2.414.46-node.23
9.11.1 v8 6.2.414.46-node.23
9.11.0 v8 6.2.414.46-node.23
9.10.1 v8 6.2.414.46-node.23
9.10.0 v8 6.2.414.46-node.23
9.9.0 v8 6.2.414.46-node.22
9.8.0 v8 6.2.414.46-node.21
9.7.1 v8 6.2.414.46-node.20
9.7.0 v8 6.2.414.46-node.20
9.6.1 v8 6.2.414.46-node.20
9.6.0 v8 6.2.414.46-node.20
9.5.0 v8 6.2.414.46-node.18
9.4.0 v8 6.2.414.46-node.17
9.3.0 v8 6.2.414.46-node.15
9.2.1 v8 6.2.414.44-node.11
9.2.0 v8 6.2.414.44-node.11
9.1.0 v8 6.2.414.32-node.8
9.0.0 v8 6.2.414.32-node.8
8.16.2 v8 6.2.414.78
8.16.1 v8 6.2.414.77
8.16.0 v8 6.2.414.77
8.15.1 v8 6.2.414.75
8.15.0 v8 6.2.414.75
8.14.1 v8 6.2.414.75
8.14.0 v8 6.2.414.72
8.13.0 v8 6.2.414.72
8.12.0 v8 6.2.414.66
8.11.4 v8 6.2.414.54
8.11.3 v8 6.2.414.54
8.11.2 v8 6.2.414.54
8.11.1 v8 6.2.414.50
8.11.0 v8 6.2.414.50
8.10.0 v8 6.2.414.50
0% complete0% complete 		8.9.4
(these versions have identical results)
8.9.4 v8 6.1.534.50
8.9.3 v8 6.1.534.48
8.9.2 v8 6.1.534.48
8.9.1 v8 6.1.534.47
8.9.0 v8 6.1.534.46
8.8.1 v8 6.1.534.42
8.8.0 v8 6.1.534.42
8.7.0 v8 6.1.534.42
0% complete0% complete 		8.6.0
(these versions have identical results)
8.6.0 v8 6.0.287.53
8.5.0 v8 6.0.287.53
8.4.0 v8 6.0.286.52
8.3.0 v8 6.0.286.52
0% complete0% complete 		8.2.1
(these versions have identical results)
8.2.1 v8 5.8.283.41
8.2.0 v8 5.8.283.41
8.1.4 v8 5.8.283.41
8.1.3 v8 5.8.283.41
8.1.2 v8 5.8.283.41
8.1.1 v8 5.8.283.41
8.1.0 v8 5.8.283.41
8.0.0 v8 5.8.283.41
0% complete0% complete 		7.10.1
(these versions have identical results)
7.10.1 v8 5.5.372.43
7.10.0 v8 5.5.372.43
7.9.0 v8 5.5.372.43
7.8.0 v8 5.5.372.43
7.7.4 v8 5.5.372.42
7.7.3 v8 5.5.372.41
7.7.2 v8 5.5.372.41
7.7.1 v8 5.5.372.41
7.7.0 v8 5.5.372.41
7.6.0 v8 5.5.372.40
0% complete0% complete 		7.5.0
(these versions have identical results)
7.5.0 v8 5.4.500.48
7.4.0 v8 5.4.500.45
7.3.0 v8 5.4.500.45
7.2.1 v8 5.4.500.44
7.2.0 v8 5.4.500.43
7.1.0 v8 5.4.500.36
7.0.0 v8 5.4.500.36
0% complete0% complete 		6.17.1
(these versions have identical results)
6.17.1 v8 5.1.281.111
6.17.0 v8 5.1.281.111
6.16.0 v8 5.1.281.111
6.15.1 v8 5.1.281.111
6.15.0 v8 5.1.281.111
6.14.4 v8 5.1.281.111
6.14.3 v8 5.1.281.111
6.14.2 v8 5.1.281.111
6.14.1 v8 5.1.281.111
6.14.0 v8 5.1.281.111
6.13.1 v8 5.1.281.111
6.13.0 v8 5.1.281.111
6.12.3 v8 5.1.281.111
6.12.2 v8 5.1.281.109
6.12.1 v8 5.1.281.109
6.12.0 v8 5.1.281.108
6.11.5 v8 5.1.281.108
6.11.4 v8 5.1.281.108
6.11.3 v8 5.1.281.107
6.11.2 v8 5.1.281.103
6.11.1 v8 5.1.281.103
6.11.0 v8 5.1.281.102
6.10.3 v8 5.1.281.101
6.10.2 v8 5.1.281.98
6.10.1 v8 5.1.281.95
6.10.0 v8 5.1.281.93
6.9.5 v8 5.1.281.89
6.9.4 v8 5.1.281.89
6.9.3 v8 5.1.281.89
6.9.2 v8 5.1.281.88
6.9.1 v8 5.1.281.84
6.9.0 v8 5.1.281.84
6.8.1 v8 5.1.281.84
6.8.0 v8 5.1.281.84
6.7.0 v8 5.1.281.83
6.6.0 v8 5.1.281.83
6.5.0 v8 5.1.281.81
0% complete0% complete 		6.4.0
(these versions have identical results)
6.4.0 v8 5.0.71.60
6.3.1 v8 5.0.71.57
6.3.0 v8 5.0.71.52
6.2.2 v8 5.0.71.52
6.2.1 v8 5.0.71.52
6.2.0 v8 5.0.71.47
6.1.0 v8 5.0.71.35
6.0.0 v8 5.0.71.35
0% complete0% complete 		5.12.0
(these versions have identical results)
5.12.0 v8 4.6.85.32
5.11.1 v8 4.6.85.31
5.11.0 v8 4.6.85.31
5.10.1 v8 4.6.85.31
5.10.0 v8 4.6.85.31
5.9.1 v8 4.6.85.31
5.9.0 v8 4.6.85.31
5.8.0 v8 4.6.85.31
5.7.1 v8 4.6.85.31
5.7.0 v8 4.6.85.31
5.6.0 v8 4.6.85.31
5.5.0 v8 4.6.85.31
5.4.1 v8 4.6.85.31
5.4.0 v8 4.6.85.31
5.3.0 v8 4.6.85.31
5.2.0 v8 4.6.85.31
5.1.1 v8 4.6.85.31
5.1.0 v8 4.6.85.31
5.0.0 v8 4.6.85.28
0% complete0% complete 		4.9.1
(these versions have identical results)
4.9.1 v8 4.5.103.53
4.9.0 v8 4.5.103.53
4.8.7 v8 4.5.103.53
4.8.6 v8 4.5.103.53
4.8.5 v8 4.5.103.47
4.8.4 v8 4.5.103.47
4.8.3 v8 4.5.103.47
4.8.2 v8 4.5.103.46
4.8.1 v8 4.5.103.46
4.8.0 v8 4.5.103.45
4.7.3 v8 4.5.103.43
4.7.2 v8 4.5.103.43
4.7.1 v8 4.5.103.43
4.7.0 v8 4.5.103.43
4.6.2 v8 4.5.103.42
4.6.1 v8 4.5.103.37
4.6.0 v8 4.5.103.37
4.5.0 v8 4.5.103.37
4.4.7 v8 4.5.103.36
4.4.6 v8 4.5.103.36
4.4.5 v8 4.5.103.35
4.4.4 v8 4.5.103.35
4.4.3 v8 4.5.103.35
4.4.2 v8 4.5.103.35
4.4.1 v8 4.5.103.35
4.4.0 v8 4.5.103.35
4.3.2 v8 4.5.103.35
4.3.1 v8 4.5.103.35
4.3.0 v8 4.5.103.35
4.2.6 v8 4.5.103.35
4.2.5 v8 4.5.103.35
4.2.4 v8 4.5.103.35
4.2.3 v8 4.5.103.35
4.2.2 v8 4.5.103.35
4.2.1 v8 4.5.103.35
4.2.0 v8 4.5.103.35
4.1.2 v8 4.5.103.35
4.1.1 v8 4.5.103.33
4.1.0 v8 4.5.103.33
4.0.0 v8 4.5.103.30
0% complete0% complete 		0.12.18
(these versions have identical results)
0.12.18 v8 3.28.71.20
0% complete% complete 		0.10.48
(these versions have identical results)
0.10.48 v8 3.14.5.11
% complete% complete

features

String.prototype.matchAll

§basic functionality
?
function(){
var iterator = '11a2bb'.matchAll(/(\d)(\D)/g); if(iterator[Symbol.iterator]() !== iterator)return false; var a = '', b = '', c = '', step; while(!(step = iterator.next()).done){ a += step.value[0]; b += step.value[1]; c += step.value[2]; } return a === '1a2b' && b === '12' && c === 'ab';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
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Error
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Error
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No
Error
No
No
§throws on non-global regex
?
function(){
if (typeof String.prototype.matchAll !== 'function') return false; try { '11a2bb'.matchAll(/(\d)(\D)/); } catch (e) { return true; }
}
No
No
No
No
No
No
No
No
No
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No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No

BigInt

§basic functionality
?
function(){
return (1n + 2n) === 3n;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Error
Error
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No
Error
No
No
§constructor
?
function(){
return BigInt("3") === 3n;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
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Error
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Error
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Error
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Error
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No
Error
No
No
§BigInt.asUintN
?
function(){
return typeof BigInt.asUintN === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
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Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No
§BigInt.asIntN
?
function(){
return typeof BigInt.asIntN === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
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Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
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Error
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Error
Error
No
Error
No
No
§BigInt64Array
?
function(){
var buffer = new ArrayBuffer(64); var view = new BigInt64Array(buffer); view[0] = 0x8000000000000000n; return view[0] === -0x8000000000000000n;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No
§BigUint64Array
?
function(){
var buffer = new ArrayBuffer(64); var view = new BigUint64Array(buffer); view[0] = 0x10000000000000000n; return view[0] === 0n;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No
§DataView.prototype.getBigInt64
?
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setBigInt64(0, 1n); return view.getBigInt64(0) === 1n;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No
§DataView.prototype.getBigUint64
?
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setBigUint64(0, 1n); return view.getBigUint64(0) === 1n;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No

§Promise.allSettled
?
function(){
Promise.allSettled([ Promise.resolve(1), Promise.reject(2), Promise.resolve(3) ]).then(it => { if ( it.length === 3 && it[0].status === 'fulfilled' && it[0].value === 1 && it[1].status === 'rejected' && it[1].reason === 2 && it[2].status === 'fulfilled' && it[2].value === 3 ) asyncTestPassed(); });
}
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No

globalThis

§"globalThis" global property is global object
?
function(){
var actualGlobal = Function('return this')(); actualGlobal.__system_global_test__ = 42; return typeof globalThis === 'object' && globalThis && globalThis === actualGlobal && !globalThis.lacksGlobalThis && globalThis.__system_global_test__ === 42;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
§"globalThis" global property has correct property descriptor
?
function(){
var actualGlobal = Function('return this')(); if (typeof globalThis !== 'object') { return false; } if (!('globalThis' in actualGlobal)) { return false; } if (Object.prototype.propertyIsEnumerable.call(actualGlobal, 'globalThis')) { return false; } var descriptor = Object.getOwnPropertyDescriptor(actualGlobal, 'globalThis'); return descriptor.value === actualGlobal && !descriptor.enumerable && descriptor.configurable && descriptor.writable;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
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No
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No
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No
No
No
No
No

Node.js ESNEXT Support

14.0.0
(these versions have identical results)
nightly v8 7.8.279.17-node.19
Nightly!5% complete5% complete 		13.0.1
(these versions have identical results)
13.0.1 v8 7.8.279.17-node.14
13.0.0 v8 7.8.279.17-node.14
12.13.0 v8 7.7.299.13-node.12
12.12.0 v8 7.7.299.13-node.12
12.11.1 v8 7.7.299.11-node.12
12.11.0 v8 7.7.299.11-node.12
5% complete5% complete 		12.10.0
(these versions have identical results)
12.10.0 v8 7.6.303.29-node.16
12.9.1 v8 7.6.303.29-node.15
12.9.0 v8 7.6.303.29-node.15
5% complete5% complete 		12.8.1
(these versions have identical results)
12.8.1 v8 7.5.288.22-node.16
12.8.0 v8 7.5.288.22-node.16
12.7.0 v8 7.5.288.22-node.16
12.6.0 v8 7.5.288.22-node.14
12.5.0 v8 7.5.288.22-node.14
5% complete5% complete 		12.4.0
(these versions have identical results)
12.4.0 v8 7.4.288.27-node.18
12.3.1 v8 7.4.288.27-node.18
12.3.0 v8 7.4.288.27-node.17
12.2.0 v8 7.4.288.21-node.17
12.1.0 v8 7.4.288.21-node.16
12.0.0 v8 7.4.288.21-node.16
5% complete4% complete 		11.15.0
(these versions have identical results)
11.15.0 v8 7.0.276.38-node.19
11.14.0 v8 7.0.276.38-node.18
11.13.0 v8 7.0.276.38-node.18
11.12.0 v8 7.0.276.38-node.18
11.11.0 v8 7.0.276.38-node.18
11.10.1 v8 7.0.276.38-node.17
11.10.0 v8 7.0.276.38-node.17
11.9.0 v8 7.0.276.38-node.16
11.8.0 v8 7.0.276.38-node.16
11.7.0 v8 7.0.276.38-node.16
11.6.0 v8 7.0.276.38-node.13
11.5.0 v8 7.0.276.38-node.13
11.4.0 v8 7.0.276.38-node.13
11.3.0 v8 7.0.276.38-node.11
11.2.0 v8 7.0.276.38-node.11
11.1.0 v8 7.0.276.32-node.7
11.0.0 v8 7.0.276.28-node.5
3% complete1% complete 		10.17.0
(these versions have identical results)
10.17.0 v8 6.8.275.32-node.54
10.16.3 v8 6.8.275.32-node.54
10.16.2 v8 6.8.275.32-node.54
10.16.1 v8 6.8.275.32-node.54
10.16.0 v8 6.8.275.32-node.52
10.15.3 v8 6.8.275.32-node.51
10.15.2 v8 6.8.275.32-node.12
10.15.1 v8 6.8.275.32-node.12
10.15.0 v8 6.8.275.32-node.45
10.14.2 v8 6.8.275.32-node.45
10.14.1 v8 6.8.275.32-node.36
10.14.0 v8 6.8.275.32-node.36
10.13.0 v8 6.8.275.32-node.36
10.12.0 v8 6.8.275.32-node.35
10.11.0 v8 6.8.275.32-node.28
10.10.0 v8 6.8.275.30-node.24
10.9.0 v8 6.8.275.24-node.14
3% complete1% complete 		10.8.0
(these versions have identical results)
10.8.0 v8 6.7.288.49-node.19
10.7.0 v8 6.7.288.49-node.15
10.6.0 v8 6.7.288.46-node.13
10.5.0 v8 6.7.288.46-node.8
10.4.1 v8 6.7.288.45-node.7
10.4.0 v8 6.7.288.43-node.7
3% complete1% complete 		10.3.0
(these versions have identical results)
10.3.0 v8 6.6.346.32-node.9
10.2.1 v8 6.6.346.32-node.8
10.2.0 v8 6.6.346.32-node.8
10.1.0 v8 6.6.346.27-node.6
10.0.0 v8 6.6.346.24-node.5
3% complete1% complete 		9.11.2
(these versions have identical results)
9.11.2 v8 6.2.414.46-node.23
9.11.1 v8 6.2.414.46-node.23
9.11.0 v8 6.2.414.46-node.23
9.10.1 v8 6.2.414.46-node.23
9.10.0 v8 6.2.414.46-node.23
9.9.0 v8 6.2.414.46-node.22
9.8.0 v8 6.2.414.46-node.21
9.7.1 v8 6.2.414.46-node.20
9.7.0 v8 6.2.414.46-node.20
9.6.1 v8 6.2.414.46-node.20
9.6.0 v8 6.2.414.46-node.20
9.5.0 v8 6.2.414.46-node.18
9.4.0 v8 6.2.414.46-node.17
9.3.0 v8 6.2.414.46-node.15
9.2.1 v8 6.2.414.44-node.11
9.2.0 v8 6.2.414.44-node.11
9.1.0 v8 6.2.414.32-node.8
9.0.0 v8 6.2.414.32-node.8
8.16.2 v8 6.2.414.78
8.16.1 v8 6.2.414.77
8.16.0 v8 6.2.414.77
8.15.1 v8 6.2.414.75
8.15.0 v8 6.2.414.75
8.14.1 v8 6.2.414.75
8.14.0 v8 6.2.414.72
8.13.0 v8 6.2.414.72
8.12.0 v8 6.2.414.66
8.11.4 v8 6.2.414.54
8.11.3 v8 6.2.414.54
8.11.2 v8 6.2.414.54
8.11.1 v8 6.2.414.50
8.11.0 v8 6.2.414.50
8.10.0 v8 6.2.414.50
1% complete1% complete 		8.9.4
(these versions have identical results)
8.9.4 v8 6.1.534.50
8.9.3 v8 6.1.534.48
8.9.2 v8 6.1.534.48
8.9.1 v8 6.1.534.47
8.9.0 v8 6.1.534.46
8.8.1 v8 6.1.534.42
8.8.0 v8 6.1.534.42
8.7.0 v8 6.1.534.42
1% complete1% complete 		8.6.0
(these versions have identical results)
8.6.0 v8 6.0.287.53
8.5.0 v8 6.0.287.53
8.4.0 v8 6.0.286.52
8.3.0 v8 6.0.286.52
1% complete1% complete 		8.2.1
(these versions have identical results)
8.2.1 v8 5.8.283.41
8.2.0 v8 5.8.283.41
8.1.4 v8 5.8.283.41
8.1.3 v8 5.8.283.41
8.1.2 v8 5.8.283.41
8.1.1 v8 5.8.283.41
8.1.0 v8 5.8.283.41
8.0.0 v8 5.8.283.41
1% complete1% complete 		7.10.1
(these versions have identical results)
7.10.1 v8 5.5.372.43
7.10.0 v8 5.5.372.43
7.9.0 v8 5.5.372.43
7.8.0 v8 5.5.372.43
7.7.4 v8 5.5.372.42
7.7.3 v8 5.5.372.41
7.7.2 v8 5.5.372.41
7.7.1 v8 5.5.372.41
7.7.0 v8 5.5.372.41
7.6.0 v8 5.5.372.40
1% complete1% complete 		7.5.0
(these versions have identical results)
7.5.0 v8 5.4.500.48
7.4.0 v8 5.4.500.45
7.3.0 v8 5.4.500.45
7.2.1 v8 5.4.500.44
7.2.0 v8 5.4.500.43
7.1.0 v8 5.4.500.36
7.0.0 v8 5.4.500.36
1% complete1% complete 		6.17.1
(these versions have identical results)
6.17.1 v8 5.1.281.111
6.17.0 v8 5.1.281.111
6.16.0 v8 5.1.281.111
6.15.1 v8 5.1.281.111
6.15.0 v8 5.1.281.111
6.14.4 v8 5.1.281.111
6.14.3 v8 5.1.281.111
6.14.2 v8 5.1.281.111
6.14.1 v8 5.1.281.111
6.14.0 v8 5.1.281.111
6.13.1 v8 5.1.281.111
6.13.0 v8 5.1.281.111
6.12.3 v8 5.1.281.111
6.12.2 v8 5.1.281.109
6.12.1 v8 5.1.281.109
6.12.0 v8 5.1.281.108
6.11.5 v8 5.1.281.108
6.11.4 v8 5.1.281.108
6.11.3 v8 5.1.281.107
6.11.2 v8 5.1.281.103
6.11.1 v8 5.1.281.103
6.11.0 v8 5.1.281.102
6.10.3 v8 5.1.281.101
6.10.2 v8 5.1.281.98
6.10.1 v8 5.1.281.95
6.10.0 v8 5.1.281.93
6.9.5 v8 5.1.281.89
6.9.4 v8 5.1.281.89
6.9.3 v8 5.1.281.89
6.9.2 v8 5.1.281.88
6.9.1 v8 5.1.281.84
6.9.0 v8 5.1.281.84
6.8.1 v8 5.1.281.84
6.8.0 v8 5.1.281.84
6.7.0 v8 5.1.281.83
6.6.0 v8 5.1.281.83
6.5.0 v8 5.1.281.81
1% complete1% complete 		6.4.0
(these versions have identical results)
6.4.0 v8 5.0.71.60
6.3.1 v8 5.0.71.57
6.3.0 v8 5.0.71.52
6.2.2 v8 5.0.71.52
6.2.1 v8 5.0.71.52
6.2.0 v8 5.0.71.47
6.1.0 v8 5.0.71.35
6.0.0 v8 5.0.71.35
1% complete1% complete 		5.12.0
(these versions have identical results)
5.12.0 v8 4.6.85.32
5.11.1 v8 4.6.85.31
5.11.0 v8 4.6.85.31
5.10.1 v8 4.6.85.31
5.10.0 v8 4.6.85.31
5.9.1 v8 4.6.85.31
5.9.0 v8 4.6.85.31
5.8.0 v8 4.6.85.31
5.7.1 v8 4.6.85.31
5.7.0 v8 4.6.85.31
5.6.0 v8 4.6.85.31
5.5.0 v8 4.6.85.31
5.4.1 v8 4.6.85.31
5.4.0 v8 4.6.85.31
5.3.0 v8 4.6.85.31
5.2.0 v8 4.6.85.31
5.1.1 v8 4.6.85.31
5.1.0 v8 4.6.85.31
5.0.0 v8 4.6.85.28
1% complete1% complete 		4.9.1
(these versions have identical results)
4.9.1 v8 4.5.103.53
4.9.0 v8 4.5.103.53
4.8.7 v8 4.5.103.53
4.8.6 v8 4.5.103.53
4.8.5 v8 4.5.103.47
4.8.4 v8 4.5.103.47
4.8.3 v8 4.5.103.47
4.8.2 v8 4.5.103.46
4.8.1 v8 4.5.103.46
4.8.0 v8 4.5.103.45
4.7.3 v8 4.5.103.43
4.7.2 v8 4.5.103.43
4.7.1 v8 4.5.103.43
4.7.0 v8 4.5.103.43
4.6.2 v8 4.5.103.42
4.6.1 v8 4.5.103.37
4.6.0 v8 4.5.103.37
4.5.0 v8 4.5.103.37
4.4.7 v8 4.5.103.36
4.4.6 v8 4.5.103.36
4.4.5 v8 4.5.103.35
4.4.4 v8 4.5.103.35
4.4.3 v8 4.5.103.35
4.4.2 v8 4.5.103.35
4.4.1 v8 4.5.103.35
4.4.0 v8 4.5.103.35
4.3.2 v8 4.5.103.35
4.3.1 v8 4.5.103.35
4.3.0 v8 4.5.103.35
4.2.6 v8 4.5.103.35
4.2.5 v8 4.5.103.35
4.2.4 v8 4.5.103.35
4.2.3 v8 4.5.103.35
4.2.2 v8 4.5.103.35
4.2.1 v8 4.5.103.35
4.2.0 v8 4.5.103.35
4.1.2 v8 4.5.103.35
4.1.1 v8 4.5.103.33
4.1.0 v8 4.5.103.33
4.0.0 v8 4.5.103.30
1% complete1% complete 		0.12.18
(these versions have identical results)
0.12.18 v8 3.28.71.20
1% complete1% complete 		0.10.48
(these versions have identical results)
0.10.48 v8 3.14.5.11
1% complete1% complete

candidate (stage 3)

WeakReferences

§WeakRef minimal support
?
function(){
var O = {}; var weakref = new WeakRef(O); return weakref.deref() === O;
}
Error
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No
Error
No
No
§Finalizers minimal support
?
function(){
var fg = new FinalizationGroup(function() {}); return Object.getPrototypeOf(fg) === FinalizationGroup.prototype;
}
Error
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No
Error
No
No

instance class fields

§public instance class fields
?
function(){
class C { x = 'x'; } return new C().x === 'x';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
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§private instance class fields basic support
?
function(){
class C { #x; constructor(x){ this.#x = x; } x(){ return this.#x; } } return new C(42).x() === 42;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
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§private instance class fields initializers
?
function(){
class C { #x = 42; x(){ return this.#x; } } return new C().x() === 42;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
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§computed instance class fields
?
function(){
class C { ['x'] = 42; } return new C().x === 42;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
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Error
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No
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No
No

static class fields

§public static class fields
?
function(){
class C { static x = 'x'; } return C.x === 'x';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
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No
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No
No
§private static class fields
?
function(){
class C { static #x = 42; x(){ return C.#x; } } return new C().x() === 42;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
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No
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No
No
§computed static class fields
?
function(){
class C { static ['x'] = 42; } return C.x === 42;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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No
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No
No

optional chaining operator (?.)

§optional property access
?
function(){
var foo = { baz: 42 }; var bar = null; return foo?.baz === 42 && bar?.baz === undefined;
}
Error
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No
Error
No
No
§optional bracket access
?
function(){
var foo = { baz: 42 }; var bar = null; return foo?.['baz'] === 42 && bar?.['baz'] === undefined;
}
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No
Error
No
No
§optional method call
?
function(){
var foo = { baz: function () { return 42; } }; var bar = null; return foo?.baz() === 42 && bar?.baz() === undefined;
}
Error
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No
Error
No
No

§nullish coalescing operator (??)
?
function(){
return null ?? 42 === 42 && undefined ?? 42 === 42 && false ?? 42 === false && '' ?? 42 === '' && 0 ?? 42 === 0;
}
Error
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No
Error
No
No
§numeric separators
?
function(){
return 1_000_000.000_001 === 1000000.000001 && 0b1010_0001_1000_0101 === 0b1010000110000101;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
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§String.prototype.replaceAll
?
function(){
return 'q=query+string+parameters'.replaceAll('+', ' ') === 'q=query string parameters';
}
Error
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No
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No
No
§Promise.any
?
function(){
Promise.any([ Promise.resolve(1), Promise.reject(2), Promise.resolve(3) ]).then(it => { if (it === 1) asyncTestPassed(); });
}
Error
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No
Error
No
No

Legacy RegExp features in JavaScript

§RegExp "lastMatch"
?
function(){
var re = /\w/; re.exec('x'); return RegExp.lastMatch === 'x';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
§RegExp.$1-$9
?
function(){
for (var i = 1; i < 10; i++) { if (!(('$' + i) in RegExp)) return false; } return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No

draft (stage 2)

§Generator function.sent Meta Property
?
function(){
var result; function* generator() { result = function.sent; } var iter = generator(); iter.next('tromple'); return result === 'tromple';
}
Error
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§Realms
?
function(){
return typeof Realm === "function" && ["eval", "global", "intrinsics", "stdlib", "directEval", "indirectEval", "initGlobal", "nonEval"].every(function(key){ return key in Realm.prototype; });
}
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
§Array.isTemplateObject
?
function(){
return !Array.isTemplateObject([]) && Array.isTemplateObject((it => it)`a{1}c`);
}
Error
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No
Error
No
No

Class and Property Decorators

§class decorators
?
function(){
class A { @nonconf get B() {} } function nonconf(target, name, descriptor) { descriptor.configurable = false; return descriptor; } return Object.getOwnPropertyDescriptor(A.prototype, "B").configurable === false;
}
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throw expressions

§logical
?
function(){
var a, b; try { a = 19 || throw 77; b = 88 && throw 23; } catch (e) { return a + e === 42; }
}
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§parameter initializers
?
function(){
function fn (arg = throw 42) { return arg; } if (fn(21) !== 21) return false; try { fn(); } catch (e) { return e === 42; }
}
Error
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§arrow function bodies
?
function(){
var fn = () => throw 42; try { fn(); } catch (e) { return e === 42; }
}
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§conditionals
?
function(){
true ? 42 : throw 21; try { false ? 42 : throw 21; } catch (e) { return e === 21; }
}
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Set methods

§Set.prototype.intersection
?
function(){
var set = new Set([1, 2, 3]).intersection(new Set([2, 3, 4])); return set.size === 2 && set.has(2) && set.has(3);
}
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No
Error
No
No
§Set.prototype.union
?
function(){
var set = new Set([1, 2]).union(new Set([2, 3])); return set.size === 3 && set.has(1) && set.has(2) && set.has(3);
}
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No
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No
No
§Set.prototype.difference
?
function(){
var set = new Set([1, 2, 3]).difference(new Set([3, 4])); return set.size === 2 && set.has(1) && set.has(2);
}
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No
Error
No
No
§Set.prototype.symmetricDifference
?
function(){
var set = new Set([1, 2]).symmetricDifference(new Set([2, 3])); return set.size === 2 && set.has(1) && set.has(3);
}
Error
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No
Error
No
No
§Set.prototype.isDisjointFrom
?
function(){
return new Set([1, 2, 3]).isDisjointFrom([4, 5, 6]);
}
Error
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Error
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No
Error
No
No
§Set.prototype.isSubsetOf
?
function(){
return new Set([1, 2, 3]).isSubsetOf([5, 4, 3, 2, 1]);
}
Error
Error
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Error
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No
Error
No
No
§Set.prototype.isSupersetOf
?
function(){
return new Set([5, 4, 3, 2, 1]).isSupersetOf([1, 2, 3]);
}
Error
Error
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Error
Error
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No
Error
No
No

ArrayBuffer.prototype.transfer

§ArrayBuffer.prototype.transfer()
?
function(){
const buffer1 = new Uint8Array([1, 2]).buffer; const buffer2 = buffer1.transfer(); return buffer1.byteLength === 0 && buffer2.byteLength === 2;
}
Error
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No
Error
No
No
§ArrayBuffer.prototype.realloc()
?
function(){
const buffer1 = new ArrayBuffer(1024); const buffer2 = buffer1.realloc(256); return buffer1.byteLength === 0 && buffer2.byteLength === 256;
}
Error
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Error
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Error
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Error
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No
Error
No
No

Map.prototype.upsert

§Map.prototype.upsert
?
function(){
const map = new Map([['a', 1]]); if (map.upsert('a', it => 2, () => 3) !== 2) return false; if (map.upsert('b', it => 2, () => 3) !== 3) return false; return Array.from(map).join() === 'a,2,b,3';
}
Error
Error
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Error
Error
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Error
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Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No
§WeakMap.prototype.upsert
?
function(){
const a = {}, b = {}; const map = new WeakMap([[a, 1]]); if (map.upsert(a, it => 2, () => 3) !== 2) return false; if (map.upsert(b, it => 2, () => 3) !== 3) return false; return map.get(a) === 2 && map.get(b) === 3;
}
Error
Error
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Error
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Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No

Iterator Helpers

§instanceof Iterator
?
function(){
return [1, 2, 3].values() instanceof Iterator;
}
Error
Error
Error
Error
Error
Error
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Error
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Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No
§extends Iterator
?
function(){
class Class extends Iterator { } const instance = new Class(); return instance[Symbol.iterator]() === instance;
}
Error
Error
Error
Error
Error
Error
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Error
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Error
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Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No
§Iterator.from, iterable
?
function(){
const iterator = Iterator.from([1, 2, 3]); return 'next' in iterator && iterator instanceof Iterator && Array.from(iterator).join() === '1,2,3';
}
Error
Error
Error
Error
Error
Error
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Error
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Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
No
Error
No
No
§Iterator.from, iterator
?
function(){
const iterator = Iterator.from({ i: 0, next() { return { value: ++this.i, done: this.i > 3 }; } }); return 'next' in iterator && iterator instanceof Iterator && Array.from(iterator).join() === '1,2,3';
}
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§Iterator.prototype.asIndexedPairs
?
function(){
return Array.from([1, 2, 3].values().asIndexedPairs()).join() === '0,1,1,2,2,3';
}
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§Iterator.prototype.drop
?
function(){
return Array.from([1, 2, 3].values().drop(1)).join() === '2,3';
}
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§Iterator.prototype.every
?
function(){
return [1, 2, 3].values().every(it => typeof it === 'number');
}
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§Iterator.prototype.filter
?
function(){
return Array.from([1, 2, 3].values().filter(it => it % 2)).join() === '1,3';
}
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§Iterator.prototype.find
?
function(){
return [1, 2, 3].values().find(it => it % 2) === 1;
}
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§Iterator.prototype.flatMap
?
function(){
return Array.from([1, 2, 3].values().flatMap(it => [it, 0])).join() === '1,0,2,0,3,0';
}
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§Iterator.prototype.forEach
?
function(){
let result = ''; [1, 2, 3].values().forEach(it => result += it); return result === '123';
}
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§Iterator.prototype.map
?
function(){
return Array.from([1, 2, 3].values().map(it => it * it)).join() === '1,4,9';
}
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§Iterator.prototype.reduce
?
function(){
return [1, 2, 3].values().reduce((a, b) => a + b) === 6;
}
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§Iterator.prototype.some
?
function(){
return [1, 2, 3].values().some(it => typeof it === 'number');
}
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§Iterator.prototype.take
?
function(){
return Array.from([1, 2, 3].values().take(2)).join() === '1,2';
}
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§Iterator.prototype.toArray
?
function(){
const array = [1, 2, 3].values().toArray(); return Array.isArray(array) && array.join() === '1,2,3';
}
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§Iterator.prototype[@@toStringTag]
?
function(){
return Iterator.prototype[Symbol.toStringTag] === 'Iterator';
}
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§instanceof AsyncIterator
?
function(){
return (async function*() {})() instanceof AsyncIterator;
}
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§extends AsyncIterator
?
function(){
class Class extends AsyncIterator { } const instance = new Class(); return instance[Symbol.asyncIterator]() === instance;
}
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§AsyncIterator.from, async iterable
?
function(){
async function toArray(iterator) { const result = []; for await (const it of iterator) result.push(it); return result; } const iterator = AsyncIterator.from(async function*() { yield * [1, 2, 3] }()); if (!('next' in iterator) || !(iterator instanceof AsyncIterator)) return false; toArray(iterator).then(it => { if (it.join() === '1,2,3') asyncTestPassed(); });
}
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§AsyncIterator.from, iterable
?
function(){
async function toArray(iterator) { const result = []; for await (const it of iterator) result.push(it); return result; } const iterator = AsyncIterator.from([1, 2, 3]); if (!('next' in iterator) || !(iterator instanceof AsyncIterator)) return false; toArray(iterator).then(it => { if (it.join() === '1,2,3') asyncTestPassed(); });
}
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§AsyncIterator.from, iterator
?
function(){
async function toArray(iterator) { const result = []; for await (const it of iterator) result.push(it); return result; } const iterator = AsyncIterator.from([1, 2, 3].values()); if (!('next' in iterator) || !(iterator instanceof AsyncIterator)) return false; toArray(iterator).then(it => { if (it.join() === '1,2,3') asyncTestPassed(); });
}
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§AsyncIterator.prototype.asIndexedPairs
?
function(){
async function toArray(iterator) { const result = []; for await (const it of iterator) result.push(it); return result; } toArray((async function*() { yield * [1, 2, 3] })().asIndexedPairs()).then(it => { if (it.join() === '0,1,1,2,2,3') asyncTestPassed(); });
}
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§AsyncIterator.prototype.drop
?
function(){
async function toArray(iterator) { const result = []; for await (const it of iterator) result.push(it); return result; } toArray(async function*() { yield * [1, 2, 3] }().drop(1)).then(it => { if (it.join() === '2,3') asyncTestPassed(); });
}
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§AsyncIterator.prototype.every
?
function(){
(async function*() { yield * [1, 2, 3] })().every(it => typeof it === 'number').then(it => { if (it === true) asyncTestPassed(); });
}
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§AsyncIterator.prototype.filter
?
function(){
async function toArray(iterator) { const result = []; for await (const it of iterator) result.push(it); return result; } toArray(async function*() { yield * [1, 2, 3] }().filter(it => it % 2)).then(it => { if (it.join() === '1,3') asyncTestPassed(); });
}
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§AsyncIterator.prototype.find
?
function(){
(async function*() { yield * [1, 2, 3] })().find(it => it % 2).then(it => { if (it === 1) asyncTestPassed(); });
}
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§AsyncIterator.prototype.flatMap
?
function(){
async function toArray(iterator) { const result = []; for await (const it of iterator) result.push(it); return result; } toArray(async function*() { yield * [1, 2, 3] }().flatMap(it => [it, 0])).then(it => { if (it.join() === '1,0,2,0,3,0') asyncTestPassed(); });
}
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§AsyncIterator.prototype.forEach
?
function(){
let result = ''; (async function*() { yield * [1, 2, 3] })().forEach(it => result += it).then(() => { if (result === '123') asyncTestPassed(); });
}
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§AsyncIterator.prototype.map
?
function(){
async function toArray(iterator) { const result = []; for await (const it of iterator) result.push(it); return result; } toArray(async function*() { yield * [1, 2, 3] }().map(it => it * it)).then(it => { if (it.join() === '1,4,9') asyncTestPassed(); });
}
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§AsyncIterator.prototype.reduce
?
function(){
(async function*() { yield * [1, 2, 3] })().reduce((a, b) => a + b).then(it => { if (it === 6) asyncTestPassed(); });
}
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§AsyncIterator.prototype.some
?
function(){
(async function*() { yield * [1, 2, 3] })().some(it => typeof it === 'number').then(it => { if (it === true) asyncTestPassed(); });
}
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§AsyncIterator.prototype.take
?
function(){
async function toArray(iterator) { const result = []; for await (const it of iterator) result.push(it); return result; } toArray(async function*() { yield * [1, 2, 3] }().take(2)).then(it => { if (it.join() === '1,2') asyncTestPassed(); });
}
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§AsyncIterator.prototype.toArray
?
function(){
(async function*() { yield * [1, 2, 3] })().toArray().then(it => { if (Array.isArray(it) && it.join() === '1,2,3') asyncTestPassed(); });
}
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§AsyncIterator.prototype[@@toStringTag]
?
function(){
return AsyncIterator.prototype[Symbol.toStringTag] === 'AsyncIterator';
}
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No

proposal (stage 1)

§do expressions
?
function(){
return do { let x = 23; x + 19; } === 42;
}
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§Frozen Realms API
?
function(){
return typeof Reflect.Realm.immutableRoot === 'function' && typeof Reflect.Realm.prototype.spawn === 'function';
}
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§Math.signbit
?
function(){
return Math.signbit(NaN) === false && Math.signbit(-0) === true && Math.signbit(0) === false && Math.signbit(-42) === true && Math.signbit(42) === false;
}
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§the pipeline operator
?
function(){
function doubleSay (str) { return str + ', ' + str; } function capitalize (str) { return str[0].toUpperCase() + str.slice(1); } var result = 'hello' |> doubleSay |> capitalize |> _ => _ + '!'; return result === 'Hello, hello!';
}
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§extensible numeric literals
?
function(){
function i (str, num) { return typeof str + str + typeof num + num; } return 123i === 'string123number123';
}
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§String.prototype.codePoints
?
function(){
var results = []; for (let code of 'a𠮷b'.codePoints()) results.push(code); return results.length === 3 && results[0].codePoint === 97 && results[0].position === 0 && results[1].codePoint === 134071 && results[1].position === 1 && results[2].codePoint === 98 && results[2].position === 3;
}
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§Math.seededPRNG
?
function(){
var gen1 = Math.seededPRNG({ seed: 42 }); var gen2 = Math.seededPRNG({ seed: 42 }); if (!gen1.next || !gen1[Symbol.iterator]) return false; var first = gen1.next().value; if (first < 0 || first > 1) return false; if (first !== gen2.next().value) return false; var second = gen1.next().value; if (first === second) return false; return second === gen2.next().value;
}
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No

Observable

§basic support
?
function(){
return typeof Observable !== 'undefined';
}
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§Symbol.observable well known symbol
?
function(){
return typeof Symbol.observable === 'symbol';
}
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Error
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§Observable.prototype.subscribe
?
function(){
return 'subscribe' in Observable.prototype;
}
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§Observable constructor behavior
?
function(){
if(!(new Observable(function(){}) instanceof Observable))return false; var nonCallableCheckPassed, primitiveCheckPassed, newCheckPassed; try { new Observable({ }) } catch(e) { nonCallableCheckPassed = true } try { new Observable(false) } catch(e) { primitiveCheckPassed = true } try { Observable(function() { }) } catch(e) { newCheckPassed = true } return nonCallableCheckPassed && primitiveCheckPassed && newCheckPassed;
}
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§Observable.prototype[Symbol.observable]
?
function(){
var o = new Observable(function() { }); return Symbol.observable in Observable.prototype && o[Symbol.observable]() === o;
}
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§Observable.of
?
function(){
return Observable.of(1, 2, 3) instanceof Observable;
}
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§Observable.from
?
function(){
return (Observable.from([1,2,3,4]) instanceof Observable) && (Observable.from(new Set([1, 2, 3])) instanceof Observable);
}
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Math extensions proposal

§Math.clamp
?
function(){
return Math.clamp(2, 4, 6) === 4 && Math.clamp(4, 2, 6) === 4 && Math.clamp(6, 2, 4) === 4;
}
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§Math.DEG_PER_RAD
?
function(){
return Math.DEG_PER_RAD === Math.PI / 180;
}
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§Math.degrees
?
function(){
return Math.degrees(Math.PI / 2) === 90 && Math.degrees(Math.PI) === 180;
}
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§Math.fscale
?
function(){
return Math.fscale(3, 1, 2, 1, Math.PI) === Math.fround((3 - 1) * (Math.PI - 1) / (2 - 1) + 1);
}
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§Math.RAD_PER_DEG
?
function(){
return Math.RAD_PER_DEG === 180 / Math.PI;
}
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§Math.radians
?
function(){
return Math.radians(90) === Math.PI / 2 && Math.radians(180) === Math.PI;
}
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§Math.scale
?
function(){
return Math.scale(0, 3, 5, 8, 10) === 5;
}
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Promise.try

§basic support
?
function(){
return typeof Promise.try === 'function';
}
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§returns instance of Promise
?
function(){
return Promise.try(function () {}) instanceof Promise;
}
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§call function synchronously
?
function(){
var score = 0; Promise.try(function () { score++ }); return score === 1;
}
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§function returns value
?
function(){
var score = 0; Promise.try(function() { score++; return 'foo'; }).then(function(val) { score += (val === 'foo'); if (score === 2) asyncTestPassed(); });
}
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§function throws exception
?
function(){
var score = 0; Promise.try(function() { score++; throw 'bar'; }).catch(function(err) { score += (err === 'bar'); if (score === 2) asyncTestPassed(); });
}
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§function returns fulfilled Promise
?
function(){
var score = 0; Promise.try(function() { score++; return Promise.resolve('foo'); }).then(function(val) { score += (val === 'foo'); if (score === 2) asyncTestPassed(); });
}
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§function returns rejected Promise
?
function(){
var score = 0; Promise.try(function() { score++; return Promise.reject('bar'); }).catch(function(err) { score += (err === 'bar'); if (score === 2) asyncTestPassed(); });
}
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`.of` and `.from` on collection constructors

§Map.of
?
function(){
var A = {}; var B = {}; var C = Map.of([A, 1], [B, 2]); return C.get(A) + C.get(B) === 3;
}
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§Map.from
?
function(){
var A = {}; var B = {}; var C = Map.from([[A, 1], [B, 2]], function (it) { return [it[0], it[1] + 1]; }); return C.get(A) + C.get(B) === 5;
}
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§Set.of
?
function(){
var A = {}; var B = {}; var C = Set.of(A, B); return C.has(A) + C.has(B);
}
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§Set.from
?
function(){
var C = Set.from([1, 2], function (it) { return it + 2; }); return C.has(3) + C.has(4);
}
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§WeakMap.of
?
function(){
var A = {}; var B = {}; var C = WeakMap.of([A, 1], [B, 2]); return C.get(A) + C.get(B) === 3;
}
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§WeakMap.from
?
function(){
var A = {}; var B = {}; var C = WeakMap.from([[A, 1], [B, 2]], function (it) { return [it[0], it[1] + 1]; }); return C.get(A) + C.get(B) === 5;
}
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§WeakSet.of
?
function(){
var A = {}; var B = {}; var C = WeakSet.of(A, B); return C.has(A) + C.has(B);
}
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§WeakSet.from
?
function(){
var A = {}; var B = {}; var C = WeakSet.from([A, B]); return C.has(A) + C.has(B);
}
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partial application syntax

§partial application from left
?
function(){
function f(a, b) { return a + b; }; var p = f('a', ?); return p('b') === 'ab';
}
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§partial application from right
?
function(){
function f(a, b) { return a + b; }; var p = f(?, 'b'); return p('a') === 'ab';
}
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§partial application for any arg
?
function(){
function f(a, b, c) { return a + b + c; }; var p = f(?, 'b', ?); return p('a', 'c') === 'abc';
}
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§partial application from left with rest
?
function(){
function f(a, b, c) { return a + b + c; }; var p = f('a', ...); return p('b', 'c') === 'abc';
}
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§partial application from right with rest
?
function(){
function f(a, b, c) { return a + b + c; }; var p = f(..., 'c'); return p('a', 'b') === 'abc';
}
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§partial application for any arg with rest
?
function(){
function f(a, b, c, d, e) { return a + b + c + d + e; }; var p = f(..., 'c', ...); return p('a', 'b') === 'abcab';
}
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§mixed partial application
?
function(){
function f(a, b, c, d) { return a + b + c; }; var p = f(?, 'b', ...); return p('a', 'c', 'd') === 'abcd';
}
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§runtime evaluation
?
function(){
var f = function() { throw new Error(); }; var p = f(?, 'b'); f = function(a, b) { return a + b; }; return p('a') === 'ab';
}
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§runtime evaluation of property access
?
function(){
var o = {}; var p = o.f(?, 'b'); o = { x: 'c', f: function(a, b) { return a + b + this.x; } }; return p('a') === 'abc';
}
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§lexical `this`
?
function(){
function f(a, b) { return a + b + (this === o); } var o = { f: f(?, 'b') }; return o.f('a') === 'abfalse';
}
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§constructor partial application
?
function(){
function F(a, b) { this.x = a + b; } var p = new F(?, 'b'); return p('a').x === 'ab';
}
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§constructor partial application with rest
?
function(){
function F(a, b, c) { this.x = a + b + c; } var p = new F('a', ...); return p('b', 'c').x === 'abc';
}
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Object.freeze and Object.seal syntax

§Object.freeze syntax
?
function(){
return Object.isFrozen({# foo: 42 #});
}
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§Object.freeze syntax with array literal
?
function(){
return Object.isFrozen([# 42 #]);
}
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§Object.seal syntax
?
function(){
return Object.isSealed({| foo: 42 |});
}
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§Object.seal syntax with array literal
?
function(){
return Object.isSealed([| 42 |]);
}
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§Sealing, function destructuring
?
function(){
function foo({| bar, baz |}) { return bar + baz; } if (foo({ bar: 1, baz: 2 }) !== 3) return; try { foo({ bar: 1, fuz: 2 }); } catch (e) { return true; }
}
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§Freezing, function destructuring
?
function(){
function foo({# bar, baz #}) { if (baz === 42) bar = 27; return bar + baz; } if (foo({ bar: 1, baz: 2 }) !== 3) return; try { foo({ bar: 1, baz: 42 }); } catch (e) { return true; }
}
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§Sealing, function arguments
?
function(){
function foo(| bar, baz |) { return bar + baz; } if (foo(1, 2) !== 3) return; try { foo(1, 2, 3); } catch (e) { return true; }
}
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§Freezing, function arguments
?
function(){
function foo(# bar, baz #) { if (baz === 42) bar = 27; return bar + baz; } if (foo(1, 2) !== 3) return; try { foo(1, 42); } catch (e) { return true; }
}
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Getting last item from array

§Array.prototype.lastItem
?
function(){
return [1, 2, 3].lastItem === 3;
}
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§Array.prototype.lastIndex
?
function(){
return [1, 2, 3].lastIndex === 2;
}
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Collections methods

§Map.groupBy
?
function(){
var map = Map.groupBy(new Set([1, 2, 3, 4]), it => it % 2) return map.size === 2 && map.get(0)[0] === 2 && map.get(0)[1] === 4 && map.get(1)[0] === 1 && map.get(1)[1] === 3;
}
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§Map.keyBy
?
function(){
var map = Map.keyBy(new Set([{ id: 101 }, { id: 102 }]), it => it.id) return map.size === 2 && map.get(101).id === 101 && map.get(102).id === 102;
}
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§Map.prototype.deleteAll
?
function(){
var map = new Map([[1, 2], [3, 4], [5, 6], [7, 8]]); map.deleteAll(1, 5) return map.size === 2 && map.get(3) === 4 && map.get(7) === 8;
}
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§Map.prototype.every
?
function(){
return new Map([[1, 4], [2, 5], [3, 6]]).every(it => typeof it == 'number');
}
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§Map.prototype.filter
?
function(){
var map = new Map([[1, 4], [2, 5], [3, 6]]).filter(it => !(it % 2)); return map.size === 2 && map.get(1) === 4 && map.get(3) === 6;
}
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§Map.prototype.find
?
function(){
return new Map([[1, 2], [2, 3], [3, 4]]).find(it => it % 2) === 3;
}
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§Map.prototype.findKey
?
function(){
return new Map([[1, 2], [2, 3], [3, 4]]).findKey(it => it % 2) === 2;
}
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§Map.prototype.includes
?
function(){
return new Map([[1, 2], [2, NaN]]).includes(2) && new Map([[1, 2], [2, NaN]]).includes(NaN);
}
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§Map.prototype.keyOf
?
function(){
return new Map([[1, 2], [2, NaN]]).keyOf(2) === 1 && new Map([[1, 2], [2, NaN]]).keyOf(NaN) === undefined;
}
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§Map.prototype.mapKeys
?
function(){
var map = new Map([[1, 4], [2, 5], [3, 6]]).mapKeys((value, key) => key * key); return map.size === 3 && map.get(1) === 4 && map.get(4) === 5 && map.get(9) === 6;
}
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§Map.prototype.mapValues
?
function(){
var map = new Map([[1, 4], [2, 5], [3, 6]]).mapValues((value, key) => value * value); return map.size === 3 && map.get(1) === 16 && map.get(2) === 25 && map.get(3) === 36;
}
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§Map.prototype.merge
?
function(){
var map = new Map([[1, 4], [2, 5]]).merge(new Map([[2, 7], [3, 6]])); return map.size === 3 && map.get(1) === 4 && map.get(2) === 7 && map.get(3) === 6;
}
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§Map.prototype.reduce
?
function(){
return new Map([['a', 1], ['b', 2], ['c', 3], ]).reduce(((a, b) => a + b), 1) === 7;
}
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§Map.prototype.some
?
function(){
return new Map([[1, 4], [2, 5], [3, 6]]).some(it => it % 2);
}
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§Set.prototype.addAll
?
function(){
var set = new Set([1, 2]).addAll(2, 3); return set.size === 3 && set.has(1) && set.has(2) && set.has(3);
}
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§Set.prototype.deleteAll
?
function(){
var set = new Set([1, 2, 3, 4]); return set.deleteAll(2, 3) === true && set.size === 2 && set.has(1) && set.has(4);
}
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§Set.prototype.every
?
function(){
return new Set([1, 2, 3]).every(it => typeof it === 'number');
}
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§Set.prototype.filter
?
function(){
var set = new Set([1, 2, 3]).filter(it => it % 2); return set.size === 2 && set.has(1) && set.has(3);
}
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§Set.prototype.find
?
function(){
return new Set([1, 2, 3]).find(it => !(it % 2)) === 2;
}
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§Set.prototype.join
?
function(){
return new Set([1, 2, 3]).join('|') === '1|2|3';
}
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§Set.prototype.map
?
function(){
var set = new Set([1, 2, 3]).map(it => it * it); return set.size === 3 && set.has(1) && set.has(4) && set.has(9);
}
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§Set.prototype.reduce
?
function(){
return new Set([1, 2, 3]).reduce((memo, it) => memo + it) === 6;
}
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§Set.prototype.some
?
function(){
return new Set([1, 2, 3]).some(it => it % 2);
}
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§WeakMap.prototype.deleteAll
?
function(){
var a = {}; var b = {}; var c = {}; var d = {}; var map = new WeakMap([[a, 1], [b, 2], [c, 3], [d, 4]]); map.deleteAll(a, c) return !map.has(a) && map.get(b) === 2 && !map.has(c) && map.get(d) === 4;
}
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§WeakSet.prototype.addAll
?
function(){
var a = {}; var b = {}; var c = {}; var d = {}; var set = new WeakSet([a, b]); set.addAll(c, d) return set.has(a) && set.has(b) && set.has(c) && set.has(d);
}
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§WeakSet.prototype.deleteAll
?
function(){
var a = {}; var b = {}; var c = {}; var d = {}; var set = new WeakSet([a, b, c, d]); set.deleteAll(a, c) return !set.has(a) && set.has(b) && !set.has(c) && set.has(d);
}
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{ BigInt, Number }.fromString

§Number.fromString
?
function(){
return Number.fromString('42') === 42;
}
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§BigInt.fromString
?
function(){
return BigInt.fromString('42') === 42n;
}
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strawman (stage 0)

bind (::) operator

§binary form
?
function(){
function foo() { this.garply += "foo"; return this; } var obj = { garply: "bar" }; return typeof obj::foo === "function" && obj::foo().garply === "barfoo";
}
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§unary form
?
function(){
var obj = { garply: "bar", foo: function() { this.garply += "foo"; return this; } }; return typeof ::obj.foo === "function" && ::obj.foo().garply === "barfoo";
}
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§String.prototype.at
?
function(){
return 'a𠮷b'.at(1) === '𠮷';
}
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§method parameter decorators
?
function(){
var target, key, index; function decorator(_target, _key, _index){ target = _target; key = _key; index = _index; } class C { method(@decorator foo){ } } return target === C.prototype && key === 'method' && index === 0;
}
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§function expression decorators
?
function(){
function inverse(f){ return function(){ return !f.apply(this, arguments); }; } return (@inverse function(it){ return it % 2; })(2);
}
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additional meta properties

§function.callee
?
function(){
var f = _ => function.callee === f; return f();
}
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§function.count
?
function(){
return (_ => function.count)(1, 2, 3) === 3;
}
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§function.arguments
?
function(){
var arr = (_ => function.arguments)(1, 2, 3); return Array.isArray(arr) && arr.length === 3 && arr[0] === 1 && arr[1] === 2 && arr[2] === 3;
}
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Reflect.isCallable / Reflect.isConstructor

§Reflect.isCallable
?
function(){
return Reflect.isCallable(function(){}) && Reflect.isCallable(_ => _) && !Reflect.isCallable(class {});
}
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§Reflect.isConstructor
?
function(){
return Reflect.isConstructor(function(){}) && !Reflect.isConstructor(_ => _) && Reflect.isConstructor(class {});
}
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zones

§Zone
?
function(){
return typeof Zone == 'function';
}
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§Zone.current
?
function(){
return 'current' in Zone;
}
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§Zone.prototype.name
?
function(){
return 'name' in Zone.prototype;
}
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§Zone.prototype.parent
?
function(){
return 'parent' in Zone.prototype;
}
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§Zone.prototype.fork
?
function(){
return typeof Zone.prototype.fork == 'function';
}
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§Zone.prototype.run
?
function(){
return typeof Zone.prototype.run == 'function';
}
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§Zone.prototype.wrap
?
function(){
return typeof Zone.prototype.wrap == 'function';
}
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syntactic tail calls

§direct recursion
?
function(){
"use strict"; return (function f(n){ if (n <= 0) { return "foo"; } return continue f(n - 1); }(1e6)) === "foo";
}
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§mutual recursion
?
function(){
"use strict"; function f(n){ if (n <= 0) { return "foo"; } return continue g(n - 1); } function g(n){ if (n <= 0) { return "bar"; } return continue f(n - 1); } return f(1e6) === "foo" && f(1e6+1) === "bar";
}
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object shorthand improvements

§object initializers
?
function(){
var foo = { bar: 42, baz: 33 }; var fuz = { foo.bar, foo['baz'] }; return fuz.bar === 42 && fuz.baz === 33;
}
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§destructuring assignments
?
function(){
var foo = { bar: 42, baz: 33 }; var fuz = {}; ({ fuz.bar, fuz['baz'] } = foo); return fuz.bar === 42 && fuz.baz === 33;
}
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pre-strawman

Metadata reflection API

§Reflect.defineMetadata
?
function(){
return typeof Reflect.defineMetadata == 'function';
}
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§Reflect.hasMetadata
?
function(){
return typeof Reflect.hasMetadata == 'function';
}
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§Reflect.hasOwnMetadata
?
function(){
return typeof Reflect.hasOwnMetadata == 'function';
}
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§Reflect.getMetadata
?
function(){
return typeof Reflect.getMetadata == 'function';
}
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§Reflect.getOwnMetadata
?
function(){
return typeof Reflect.getOwnMetadata == 'function';
}
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§Reflect.getMetadataKeys
?
function(){
return typeof Reflect.getMetadataKeys == 'function';
}
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§Reflect.getOwnMetadataKeys
?
function(){
return typeof Reflect.getOwnMetadataKeys == 'function';
}
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§Reflect.deleteMetadata
?
function(){
return typeof Reflect.deleteMetadata == 'function';
}
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§Reflect.metadata
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function(){
return typeof Reflect.metadata == 'function';
}
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